Well, i have a small list of things to repair on my 20th and the cruise being inop was on the list.
Yesterday i pulled pulled the car in to begin the dreaded task of trobleshooting.
gazing at the evtm..........
Key on engine off, I find power going to the cruise control box on the light blue wire, I also find power going to the cruise control box on the light green wire when the brake is applied.
I swap out cruise control units (located upper left from brake pedal). No fix.
Back to the evtm. Lets see what my steering wheel switches are doing. Remove column covers and locate the small harness that leads up to the steeriing wheel slip rings and ultimatly to the switches consisting of a blue, purple and black wire.
-Unplug the small harness and test on the sterring wheel side for conitinuity.
-hook meter up to the black and light blue
-press the OFF button and my meter beeps so this tells me i have a good path from the blue wire, through the slip ring, through the OFF side of the switch and back to the black wire. (this tells me that so far my slip rings are working).
-Hook meter up to the black and the purple wire
-Press the ON button and the meter does not BEEP>>PROBLEM
next, leave red meter lead hooked to purple wire and remove the black meter lead
pop off horn button and locate the slip ring connector at your six O'clock.
touch your black meter lead to the purple wire on the slip ring connector.
Yes, i have continuity on the PURPLE wire from the the ON side of the switch down through the slip rings and finally to the connector in the column.
Repeat for the black wire. Hook red meter lead up to the black wire on the column connector. Touch the black wire up at the slip ring connector at your six oclock under the horn button. Yes, i have continuity. I have a known good path from the column harness and through the slip rings even with i wiggle test the steering wheel.
Remove covers on the rear of the steering wheel switches.
locate wiring harness
get pissed because i cant extract the wiring from the slip ring connector
cut wires in the switch compartment
bring switch to work bench and continuity test from the black to the purple and actuate switch.
NO BEEP
SWITCH IS DEFECTIVE!!!!!!!!!!!!!!
Take switch apart by pressing out the two rivits
study its design and lift up the long metal contact
notice the red wire metal tab is worn preventing contact
To be continued,,,,,,,,,,,, Attempt to repair switch today.
I expect my cruise to be operational soon.
When you going to realize you don’t ask for advice you give it
Between you and Thunderchicken thank god I knows you guys for my electrical frustration is your advice
well, dont jump too soon,,,,,,,, NO FIX YET
I am confussed on the on and off switch. Apparently i am not suppose to have continuity from black to purple when the on is depressed. Instead i am suppose to have continuity from the purple to blue.
Moving along i remove the RESUME/SET ACCELL/COAST SWITCH
This switch has only two wires, the same black and blue from the on and off switch.
I press various buttons and have no continuity anywhere.
I take the switch apart and find a RESISTOR BANK per the shop manual pages i posted a while back.
I bend up the little metal tab back up so the switch can make contact.
Suddenly i have readings per the shop manual 125ohms, 680ohms, 2.3k ohms all showing the coast, resume and set accel is working properly.
Install both switches and NO FIX.
MOVING ALONG TO THE SERVO TEST.
I am failing the servo test when i momentarily touch circuit 145 to ground. Engine does not raise in rpm. I do hear a noise near the servo but i dont get the results in the shop manual.
If anyone has any ideas let me know. The Cruise shop manual pages are posted here i think in electrical tech.
ok,, does anyone have any experience working on the cruise servo assembly?
When i apply a momentary ground to the servo on circuit 145, i hear the servo doing something.
My first thoughts are the servo is binding up.
Does anyone have a pic of the servo asembly? Im thinking of disconnecting the cruise cable and working the cable vigerously back and forth to loosen something up. Also, im not sure how its internally designed.
My only thing left to do here is get to the servo. :mad: Lucky me
Im really beginning to think common sense here.,,,,, the servo is binding up because of the lack of use. My next trick is to spray wd40 down the vac tube leading to the servo. Hopefully some of that will drain down to a moving part. I know that the wd will get sucked back into the vac system and that really wont hurt anything. It will actually help lube up the internals of my vac actuated devices.
Who is it here who also has a 20th with an INOP cruise?
anyway,, any help would be appreciated cause this is going to be a challenge. I need to redirect my attention to control arm bushings next weekend since Napa finally got the right ones shipped. The wife is worried about the poping on the front end.
Does the horn work?
yes, horn works.
Saw this yesterday decided to thoroughly read through it. I'm the one with dead cruise.
I did some testing with the contact rings I think either from your massive DIY tutorial or from the evtm. Don't really remember what happened it was early this summer. I used ohm readings, didn't have the beeper turned on on my multimeter but I did get readings I was just going by the guidelines and they weren't quite within spec but there was obviously a connection.
I got the SAME result if you recall when I did the thing to manually override everything and jump the servo, same deal no increase in rpm but I heard a click from the servo with the engine off, and if I broke the connection then shut the engine off I heard what sounded like a hissing/air rushing noise coming from the servo.
Good point on "lack of use". Though that doesn't really apply in my case I don't think because my mom says my dad used it all the time when he bought the car and it suddenly quit I think within 1 year. No idea of its use by the previous two owners or how frequently dad used it.
I was thinking of just finding a replacement servo. I cant help but wonder if it's still somehow a similar situation to yours (if your theory is correct). If you decide to take it apart I'll be watchin'! :D Then maybe I'll try mine.
ahh
new found hope for us:hick: Im not sure why i didnt notice this earlier.
My plans to test the servo per the below drawing............
KEY OFF, ENGINE OFF TEST
step 1
-unhook the right hand connector C3003
-connect ohmeter to wires brown/light green and pink/light blue.
-meter should read about 50k ohms
step 2
-connect ohm meter to the yellow red and brown light green
-note your resistance reading
-push in the gas pedal and the resistance should smoothly change
-slowly release gas pedal and resistance should smoothly change
-connect ohm meter to the yellow/red and pink/light blue
-note your resistance reading
-push in the gas pedal and the resistance should smoothly change
-slowly release gas pedal and resistance should smoothly change
**the above two steps should be identical but opposite if i am correct.
**the above steps verified the cable to the servo moves the variable resistor on the servo and desired results proof test.
step 4
-Apply vac presure to servo vac feed and observe it holds vac
step 5
-connect ohm meter to the orange/yellow and white/pink wires
-check for a resistance of 60-190 ohms
-slowly apply vac presure to the servo vac line
-observe the resistance reading changes smoothly
-ASSUMPTION-gently press on brake pedal and vac presure will bleed off at the dump valve on brake pedal.
-observe the resistance changes smoothly
-connect ohm meter to the orange/yellow and gray/black wires
-check for a resistance of 40-125 ohms
-slowly apply vac presure to the servo vac line
-observe the resistance reading changes smoothly
-ASSUMPTION-gently press on brake pedal and vac presure will bleed off at the dump valve on brake pedal.
-observe the resistance changes smoothly
lets see if this helps any........to be continued
Re step 5.
I don't think the resistance value of the solenoids in the modulator valve are going to change with vacuum.
Test proceedure for the servo from the 84 shop manual:
With connector 3003 disconnected, do the resistance checks of the solenoid coils.
With connector 3003 still disconnected start the engine.
Connect the O/Y wire #144 to battery positive.
Connect the W/PK wire #146 to ground.
Momentarily touch the GR/BK wire #145 to ground.
The servo throttle arm should pull in and the engine speed should increase. The arm should hold in that position or slowly release.
When the W/PK wire #146 is removed from ground the servo should release.
Now I am going to read your DIY and see what it says.
Yes this agrees with what you posted from your shop manual.
After rereading the thread, it looks like you already did the servo test.
Of course the test assumes you have vacuum to the modulator valve and the brake dump valve is closed.
Is it possible that the servo cable to the throttle linkage has disconnected from the servo actuator?
You have to remove the wheel and the inner fender splash shield to check that.
my god man, you are soooooooo on the the mark!!!
SO,,, Lets both feel like idiots for a moment,,ok?
Is that,, or ,, Is that not the schematic symbol for a variable center tap resistor on wires 147-149?
It was my assumption that i could verify the throttle cable was connected by placing my ohm meter from circuit 148 to 147. When i connnected my meter up to 148 and 147, the resistance was about half (25k ohms) which i expected. I moved my gas pedal and the resistance did not change.
I was thinking right then and there i just found my problem,, my cable came unhooked!!!!!
I connected the ohm meter on 148 to 149 and moved my gas pedal. Still,,, no resistance change!!
I run out to the white cougar with working cruise control. I perform the same checks and the results were the same,,, The resistance does not change!!!!!
I am pissed......... :mad: :mad: :mad:
I thought for sure my tests would yield the same results as if you were reading a TPS,, its just a center tap resistor for christ sakes!!
SO here is what i am thinking,,,,,, maybe i need to pull a vac on the main servo vac line in order to make the resistance change. Im going back out to the garage to check that but its too dark and cold out side to verify my readings against the white cougar to proof test.
Im thinking that even if i move the pedal,, the cable is just sliding inside free inside the servo cause its not strong enough to over come the tension.
Basically, i think im working this issue backwards. I need to pull vac and then watch the resistance changes from 147 to 148 and then from 149 to 148.
make sense?
Also,, if i pull a vac on the servo assembly, the throttle linkage should also be pulled. If i see a resistance change on the meter but the throttle linkage does not pull at the throttle body, I will then know for a fact, the cable came disconnected.
Oh my God F this. LOL but seriously I love how there's about 1.3 million different things it could be. I'm seriously reading this all and shaking my head.
SHEESH, I cannot count how many times I've wanted to start a rather involved project on my car during the winter and then remembered oh wait its about 45 degrees out there I gotta turn on the elec. heater, open the basp00get door to let the warm air come up and wait like a half hour for it to come up like 10 degrees and even then I'm not 100% comfortable.
nope,,
pulling a vac on the servo does not change the resistance nor does the cable pull in at the throttle body.
I did not verify against the other coug yet.
perhaps someone can help out here.
You have the right idea about checking the center tap resister to detect servo movement.
In order for vacuum to move the servo motor (this is a vacuum motor not an electric motor) you need to energize the solenoids on the modulator valve. Just like you did when you did the servo test.
When energized, the top solenoid opens the vacuum valve and the bottom solenoid closes the vent valve. So you need them both energized to apply vacuum to the servo.
I suspect that by design the servo cable cannot push the servo motor when you step on the gas.
ahh,, i see now.
I sure couldnt tell all that by looking at the illustrated parts in the shop manual or the evtm but ill take your word.
so my plans are to **JUST** energize the modulator valve via circuits 144 and 146.
I will not do the momentary "touch" of 145 to ground. Instead,, i will pull a vac on the servo hose and check the resistance readings do vary. I should also be able to see the throttle linkage being pulled in as well ,,(that is if the cable is connected to the servo)
am I tracking you correctly?
Applying voltage to 144 and grounding 146 will close the vent valve.
Applying voltage to 144 and grounding145 will open the vacuum valve.
You need both to let the vacuum operate the servo.
so in your opinion,, since i do not have the amplifier connected and i want to do a dry test with the engine off.......
do you think it would be ok to keep the previously mentioned "momentary" ground connected long term just so i can get the modulator wired up so its open?
I want to pull my own vac with a pump and also check that variable resistor.
Yes I think that will be ok.
no, it really isnt all that complicated, im just good at over complicating simple stuff. I already know for a fact the servo is defective or the cable is undone and thats been known since probably my second post. All i wanted to do was learn the entire deal, that way i can manage to write up a simple diy for quick testing. So far , i think ive managed a single test that will do that.
dont give up so easy man:D
Yep, your right!! im glad that was your answer cause i did it. I was able to do a dry test on the system with no engine running. I appiled power to circuit 144 using the floor light connection as my source and of course, grounding circuits 145 and 146 was easy.
Results:
I was able to apply vac presure to the servo and with my ohmmeter hooked up to the pins tied to the variable resistor, i was able to see the resistance change as the servo moved.
Did i see my throttle likage move when i applied vac to the servo hose----NO
Did i fail any voltage and resistance checks--NO
Did i fail the test in the shop manual where they say to momentarily touch circuit 145 to ground --YES
I swapped in a known good amplifier and did the results change-NO
After letting a large amount of WD40 flow down to the servo, did i see any change--Yes- when the vac pump was removed the servos resistance check showed it retracted quicker than prior tests so it was slightly binding.
Did the vac dump valve operate when the brake was pressed--YES
Did the servo modulator portion hold good vac pressure--YES
In all honesty, the servo isnt failling i dont think nor is the modulator
Something tells me the servo and the amplifier are doing the correct job(s)
Its likley the cable is undone at the servo and thats all. This does not account for failing the operational test though.
I need a volunteer to do a simple test on thier car which will verify my simple three step check for the operation of the cruise which will take only 30 min of your time. All in all this have been an intersting venture into the cruise operation and im pretty comfortable now with what needs to be done to fix the problem.
tools required are:
small flat blade screw driver to pry off the two connectors.
vacuum pump hand held
one meter
5 aligator clip jumper wires
What i learned about the amplifier box-
You best just pop the back off and extract the circuit card. The color codes for some wires in the shop manual and the evtm do not match. However, the circuit numbers are stamped on the amplifier circuit card and if you just use that as your guide, you will know what wires to do what with.
I will do an easy write up if anyone wants to test thier system. I would prefer a working system to verify the one step the shop manual calls out just to see if the manual is incorrect or not. Shop manuals are not perfect. My white cougar is currenlly down due to my pending project which parts are arriving /have arrived. Thank you TOM and thank you Greg Hoag at MegaSquirt.
Well, its nice to see that people want to pitch in once in a while to learn a couple things on thier cars.
Thats ok,, someone has a broken cruise out there somewhere who's not too lazy to dig in without giving up. If no one wants to do a simple stare and compare test, thats fine with me.
Haha I will probably dive into this once again in the near future. I REALLY would like to have it. NICE tip there about the amplifier. I found the same thing, couldn't figure out the numbers, nothing matched!!! I just skimmed over that big post, I'll read this thoroughly and perform the same tests when I try it again. Honestly I can do all that just lots of text like that = me skeeeered. LOL
Next semester doesn't start 'til the 14th though so I got this week, and it's supposed to be rather nice maybe I can work outside! Lemme know what I can check out.
if you get into this,, call me. see diy link
I have one complaint here,,
if you look at the evtm page i posted,,, Why in the hell do i not have continuity for the "ON" portion of my cruise from circuits 6 to 151?
When i push the on button, i should have a continuity path and i dont. However,, when it comes time to test the on button for power delivery according to the directions , all is working fine.
Problem solved.
First pic is of the problem. The cable was not connected to the servo assembly and the clip it connects to was ripped. I will tig weld that tomorrow.
Second pic
I had to figure out a way to get slack on the cable to come to me:D . Same tool i use to hold presure on the brake pedal when i bleed them. :hick:
third pic
The broken clip and that wee tiny little snap ring. I reshaped it as close as possible in prep for tig or brazing tomorrow.
SInce all my tests prove out, and i found the cable unhooked, Problem is 99% for sure solved. Too much snow now to test out, much less get it out of my 1460ft driveway.
Here is what i think happened for the failure.
Since the cable is only there to "PULL" on the clip and de-actuate the servo or to accel, I belive that the trottle body end got in a bind during the time when the PO installed an HO upper/lower intake. Somehow the cable got yanked out of the clip and now you see the results.
What did i learn?
To test if the cable is connected, you should go directly to the throttle boday and disconnect the cruise cable. push on the cable and let it go. It should pop back out on its own because the servo spring will push the cable back. This is only true if the little ball fits or snaps into the loop around part of the clip.,,,(atleast mine will when its all said and done)
I also learned to stick to the simple stuff. If the controler does not fix the cruise and the switches are good and verfied along the underside of the steering column, then there is likely an issue with the cable. I would venture to say the cable is a large percentage of other peoples faults as well. Just remove your wheel, fender skirt, two screws holding the servo and two nuts holding the cable assembly on.
Good show!! Perseverance usualy pays off.
Can't see why your resistance check of the ON switch didn't work.
One interesting thing I noticed while studying the EVTM is the source of the voltage for the ON switch. It comes through the coil of the horn relay. In other words it is the side of the coil the horn switch grounds to pick the relay. If the horn relay coil were open, or the relay unplugged, you could not turn on the cruise.
That's why at one point I ask if the horn worked.
yeah, and when you said that,, i knew my horns both sounded kinda funny but got better after i worked them and used the car. It has sat for a while.
that part of the diagram is really stupid confussing.
well, tig welded the braket clip and it turned out good. Pic wasnt the best in the world but the clip is just fine:hick:
The driveway froze back up since it was late getting everything back together. Since the driveway is about 1,450 feet long all down hill, i figured id be smart and hold off till the daytime so i can get back up to the house.
test time tomorrow. everything went together just fine.
driveway still like a skating ring ,, not safe to attempt a return trip up the driveway, muchless down.
this is killing me waiting on some slush to happen. Its like 9degF out there right now.
I finally risked getting "Anny" down the driveway and it took six full minutes to do so feathering the Ebrake and steering the tour down hill.
I finally get to hard top,, I light up a good luck smoke and take a sip of coffee and top that off with ice breaker candy. I settle in preparing to be pampered by cruise control.
I press on
then i press set/accel and nothing.
I think back to the condition the switches were in and i repeat the above but add more presure to the switches.
IT WORKS!!!!!!!!!!!!!!!!!!!
Im sitting there just enjoying the thoughts that just in time for my road trip back to spartanburg sc, my cruise will take me there.
I look down and think,,himm,, leme wait for an up hill area and see if my cable is adjusted correctly. If my speed decreases to a certain level, passing gear should kick in before the cruise lets out.
Well,, i decide to decline on that thought because i could not wait to work the button. I pressed set / accel and nothing. It felt like set/accel shut down the cruise.
SO,,,, I press ON followed by set / accel and nothing again.
I press ON followed by set accel again and nothing.
As a matter of fact i think i pressed ON followed by set/accel pretty much for the six mile trip to the corner store before i gave in and said,,, "scott, give it up".
This is odd so i will look into this matter in the future. I have to stew on this for a while and figure out what would have cause it to work once then never again.
I will check my cable again as well as swap out amplifier modules.
If the cable and amplifier check out ok, then I will be foreced to replace the servo.
while i had the servo off, i noticed the servo wiring harness was fabricated to the servo itself with a pigtail long enough to reach the amplifier. I suppose i could take the servo apart but i will not do that until i determine the servo is good or not.
anyone wanna slush me an amplifier?
one other thing, I could have criss crossed the vac lines going to the servo but they are pretty easy to tell apart. one will not reach the others fitting. Oh well,,, to be continued.
I am going to leave the word "solved" in the tread title because I did locate the problem,, now it appears i may have to figure out what caused the problem since my prior conclusions were likely incorrect.
All is functional. Cruise is up and running perfect.
I installed a clip that arrived from vinnie earlier today and tested each and every function.
The clip vinnie sent me was slightly different from mine but i bent it a little here , and filed a little bit there and its fine.
I set my cruise down at the state park as low as 20mph and it held even going up a steep grade for about a half mile.
I tested out on the main road and upon arrival at a steep grade again, the cruise allowed passing gear to kick in.
NOW ITS SOLVED
Here's a slightly offtopic question, but with all the work you did I figure you're the guy to ask. If I wanted to trip a light when cruise is active ("speed cont" light on my modded dash), how would I do it? I figure that I might need either a relay or a TTL chip to isolate the light from whatever circuit would drive it so I don't draw much current, but what would be the best way to trip it?
http://www.foxtbirdcougarforums.com/showthread.php?t=15279
i replied to your thread,,,,,,btw,,,,
how'd you get sooooo many green boxes?
Well, after trying the electronic control troubleshooting LAST summer, as did scott more recently...I figured the servo was dead, though I couldn't be sure. After doing one of the tests, and shutting the engine down, removing one of the leads I was instructed to connect, I heard a very apparent hissing/rushing noise. Didn't know enough but I had an inkling the unit wasn't totally dead.
Today I decide to tear into the thing, sure enough what do I find...same deal, the cable was detached. Though, my clip actually snapped off before the end that's curled around to hold the at the end of the cable. Stupid y little weak-ass thing! :hick:
I pushed in the arm that obviously did the pulling on the cable, heard that familiar sound. Good news (hopefully!)
I cut up and bent some aluminum from a Lian-Li computer case optical drive slot cover, and made an entirely new clip. I throw it back together, sure enough, got cruise!!!! After at least 6 years it works finally! Sure made my dad livid when it conked out. And I made one 2.5 hr trip (each way) last summer to a big car show, and my right leg was aching by the end, so this will be very nice.
Sounds like this indeed is a very possible and likely occurrence, so check em!!!
Cheers,
Paul
dood,, you redesigned the whole clip. Your design makes it forced to stay put. I stared at the old clip and thought hard but never thought about that shape or how you shortened it up on the part where it hooks.
Kudos!!!!!!!!
Actually I should mention also that once the ball was up into the "hook" I took some electrical tape and wrapped it around the upper portion of the clip, covering the long slit I made, as well as the ball itself. I wrapped it a good 20 times around. :hick: But it held fast. I don't know if there is ever extra slack in the cable, but if there's a chance there could be I didn't want the whole thing to just slip apart in an instant over something that silly. Here's to the new clip stayin together, I don't want it to fall apart again!!! Cruise control is so FUN!!!! I just drove around town aimlessly for like 10 minutes yesterday just futzing around with it!
Checked to see why my cruise control had stopped working on my 88 Tbird sport.What I found was a broken throttle cable.Then I tried to locate a replacement cable.Nothing,part is obsolete.Does anyone know of a source.If not I guess its the salvage yard.Even that gets harder with the price of s metal.All of them are being crushed.
Then you need to simply find thin cable that is the same diameter such as bike cable / shifter or brake which has a button on on one end already. You will have to make a button for the other but that would consist of nothing more than a piece of little tubing crimped on.
I would make sure the button end of the cable was locate down at the servo. I am sure there are many resources for generic cable with buttons on one end and a crimp on button for the other.
nice work, but your leg was aching?!? Try driving from WI to CA without cruise... no sweat! :D
Made a mistake.What I needed to say was the cruise control cable was broken.