lemme start over...
My TC has an aftermarket fan control thingy that tapped into both the cooling fans. It has an adjustable thermostat, and would keep the fans running til the radiator cooled...sorta like a turbo timer. Well it was draining the battery so I took it all off and reconnected the 2 cooling fans wiring back to factory. Now the fans and AC are both inop. I ran the fan troubleshooting guide at NATO and the original IRCM wasnt working so I swapped it out. I then ran the test again and both fans worked, which means the wiring is fine all the way to the EEC(according to the NATO article). But, it still ran hot. So then I replaced the ECT. Still no good.
I then found fuse 17 blown, so I disconnected the speed control module and the rear defrost connector on the temp control panel, replaced the fuse, and started the car. As soon as I moved the lever to max ac...bam, the fuse popped. This time I disconnected the connectors at the cycling switch, AC compressor and high pressure switch, replaced the fuse and started it up. This time the fuse is good. I slowly hooked one connector up at a time, cranked it up, moved the lever to every position, and the fuse held each time. Now everything is hooked back up, the fuse held, but I still am not getting the AC or fans to work.
When I turn the key to on, the passenger fan comes on for a second like normal...other than that I just dont know. I am guessing the aftermarket system may have been installed to bypass the original problem? Dunno. Does the IRCM have any control over the AC? Also, aren't the fans supposed to come on when you select A/C?
FYI, this car has a manual temp controller.
I hope that was a typo cause other wise you just answered your own question lol.
If you have access to a good IRCM I would try that first. Those things can cause weird problems sometimes, and it is possible that the one you put it already has something wrong with it.
Also, or you
SURE you spliced the wires back like stock? If you accidentally got a pair backwards, that could also definitely cause this kinda problem...
I removed the fan portion of the alarm system. It spliced into the stock fan wiring. The fans work...they just don't come on when it gets hot.
I don't understand why fans and alarm systems would have anything to do with each other. Somebody else is gonna have to help you out here sorry
disregard the alarm part...I was just giving some background. I found fuse 17 blown. I replaced it and it blew again. This one controls a ton...including the a/c clutch. Could be a reason why an aftermarket fan controller was installed. Guess I'll be chasing down a lot of wires. :beatyoass: Not my cup of tea.
Looking at the fuse 17 circuit, I unplugged the speed controller and the rear defrost connector. I then started the car....moved the lever to a/c and, wham, the fuse blew. this is gonna suck.
You should backtrack your wiring from the ac compressor backwards. Its easy for the wiring to get pinched or smashed in something so its probably shorted or grounded to the frame causing the fuse to blow. I had a very similar situation once. I had to cut out and replace a damaged section of wiring cause it had come loose and gotten shredded somehow.
i rewrote the OP...lemme know if that's any clearer.
Well that makes more sense. The IRCM does have some control over the AC since it has to turn the fans on to pull air through the condenser. If the engine is below the necessary temp but the ac is on, it has to turn the fans on, so yes, the fans should come on when you put the switch on. This is why I was saying it could be your IRCM. The other thing I was saying is that if your fuse only blew with the ac turned on and everything else disconnected, then your problem is almost definitely somewhere in the compressor circuit. Unless you just got to bad fuses... but it could also be the case, that if something is shorting out in your IRCM that could also cause the fuse to blow. The problem in the IRCM may not always present itself. They're tricky little buggers sometimes.
Remove the connector from the AC clutch and replace the fuse and turn on the AC. If it blows again do the same with the blower circuit unless the heater works ok with the fan. Process of elimination is the key to electrical problems. Check all the components controlled by the fuse that blows. I have found many AC clutch coils draw way to much current and blow fuses. Good luck
well I have tried THREE IRCM's and still no good. The EVTM is a bit confusing. Pg 234 is a test for the control switch, but there is no listing for a c276, so I aint sure where that is. I tested the clutch coil, pressure switch on the accumulator, and even tested the diode...all are good.(pg 104 evtm) On pg 65 of the evtm...it shows a fan/control a/c pressure switch...does anyone know which one that is? There doesnt seem to be a test for that one.
Again...FYI, I did the fan test IAW NATO instructions and both fans come on. Is there a point where the 2 systems(a/c and engine temp) come together? I may just have the stereo peeps rig up a bypass like was on it.
well I have tried THREE IRCM's and still no good. The EVTM is a bit confusing. Pg 234 is a test for the control switch, but there is no listing for a c276, so I aint sure where that is. I tested the clutch coil, pressure switch on the accumulator, and even tested the diode...all are good.(pg 104 evtm) On pg 65 of the evtm...it shows a fan/control a/c pressure switch...does anyone know which one that is? There doesnt seem to be a test for that one.
Again...FYI, I did the fan test IAW NATO instructions and both fans come on. Is there a point where the 2 systems(a/c and engine temp) come together? I may just have the stereo peeps rig up a bypass like was on it.
My interpretation of the IRCM (integrated controller module) from studying the 87 EVTM.
1. The LG/P wire to the top of the Compressor Cycling Pressure Switch is 12v from fuse 17 and the dash function selector switch being in A/C.
2. The solid state block is the equivalent of the WOT cutout relay. The red wire off the page to the right of the block goes to EEC pin 54, ground at WOT.
3. Without WOT there is 12v out the bottom of the solid state block to the BK/Y wire.
4. The BK/Y wire goes to the A/C compressor clutch and to EEC pin 10. Pin 10 signals the EEC that the A/C is on.
5. Ground on the PK wire on the bottom of the secondary EDF relay will put 12v on the BR/O wire to the secondary fan. The ground is from EEC pin 52 or the Fan Control A/C Pressure Switch.
6. Voltage (not ground) on the T/O wire from EEC pin 55 to the voltage inverter below primary EDF relay will put 12v on the BR/Y wire to the primary fan.
Do you get a KOER code 21 after the engine is warmed up?
I didnt get a code, but then again I ran the test cold, just to see if the main fan came on, which it did. Everything worked fine till I pulled the aftermarket fan control mess off, so I think it was put on to bypass a problem. I am looking at the component location (pg 105) and noticed the ECA. That's the blue plastic box on the right side of the dash right? Do you know what that does? The EVTM doesnt explain it.
I have the 87 EVTM, so our pages don't match.
ECA (Electronic Control Assembly) is another name for EEC (Electronic Engine Control).
I guess technically, EEC includes all the things the ECA controls and all the sensor inputs to the ECA.
It's located behind the passenger side kick panel.
dang. thought I might have missed a component to check. Considering both fans work, what component am I missing that is not turning them on when I either 1. turn on the AC, or 2. the engine gets up to temp. I am trying to find a common component that may be broken. Is there a way to test the Engine Coolant Temp sensor? I swapped it out, but if it isnt getting a signal cuz of bad wiring, then maybe that's it?
I have never had Turbo, but I am pretty good at interpreting EVTM's.
For the A/C to turn on the fan you have to have power to the A/C compressor clutch.
Is the clutch engaging? If not maybe you are low on freon.
If you run KOER (engine running) with a cold engine, you should get a code 21. the ECT sensor indicating the engine is not warmed up.
Warm up the engine and rerun the KOER. The code 21 should go away.
Did you replace the ECT sensor with two wires to it? This is the one that goes to the EEC (ECA).
There is a one wire sensor that goes to the instrument cluster. This is not the one you want.
Are you up for some volt meter trouble shooting?
The "IRCM" is on the first Electronic Engine Control page for the 2.3L Turbo and is labeled "Integrated Controller Module.
hell yeah I am up for some voltmeter testing.
Just so ya know...everything's been working like a champ til I pulled this aftermarket wiring off. Ice cold A/C and the fans come on when hot. I replaced the ECT, but still no good, the one in the lower intake.
ECT info from the 84 Shop Manual:
50°F to 240°F Pass KOEO
180°F to 240°F Pass KOER
50°F 58.75K ohms
65°F 40.5K ohms
180°F 3.6K ohms
220°F 1.84K ohms
Code 21 Temp out of specs during self test.
Code 51 ECT shows -40° (probable is max or infininte resistance. open circuit)
Code 61 ECT shows 254° (probable is zero ohms or short circuit)
You can measure the resistance of the ECT by pulling the connector off and measuring between the ECT terminals.
When you say you ran test to see if the fan ran with the engine cold and got no code 21, I am guessing that was KOEO and not KOER. Unless it is real hot in Fla. and the engine stays above 180°
Any how with no codes 21 51 or 61 it looks like the EEC "sees" the ECT sensor ok.
When you pulled the ECT did coolant run out?
Is it possible the water jacket is gunked-up and no coolant is flowing past the ECT?
yep, I ran Key on Engine Off. I just wnated to see if the fan ran, which it did. According to NATo, that means the wring from the EEC to the fan is good. When I pulled the ECT, coolant did come out. I will do the elec check tomorrow. Poker nite tonight!;)
Look at the IRCM in your EVTM. I believe it is page 65 where you saw the Fan Control A/C Pressure Switch. The IRCM is called "Integrated Controller Module" in my EVTM.
The EEC does not know the A/C is on until you have power to the compressor clutch.
Can you back probe the connector on the IRCM without unplugging it?
The PK/LB wire to connector pin 21 from the "compressor cycling pressure switch" should have 12v with the key on and the A/C on.
You may want to check this wire to see if any "haywire" has been spliced on to it between the IRCM and the pressure switch.
Check connector pin 23 BK/Y wire for 12v. This goes to EEC pin 10 to signal the A/C is on and to the compressor clutch.
If no 12v on pin 23, check pin 22 red wire. The EEC can turn off power to the compressor clutch by putting (guessing) ground on pin 22.
You may also want to check the BK/Y wire from IRCM pin 23 to the compressor clutch to see if any non-stock wires are spliced to it.
The Fan Control A/C Pressure Switch. Not sure where it is or when it comes into play. Its' name implies it is in the A/C plumbing somewhere. If it closes the secondary fan will run if the key is on even if the A/C switch is off.
Did you ever do what Tom said? I would first of all disconnect the A/C clutch coil and see if the fuse blows. You could have a shorted one. It happens.
actually, its better to just borrow a circuit breaker fuse while troubleshooting various problems, less frustrating and the cb resets itself upon cooling down.
The fuse is good now. Dont know what happened there, I may have had a wire touching ground or something.....we called that FM(freakin magic.)
I am off to try out softtouch's idea.
Here is what I have:
W/ the engine running I checked the circuit twice, once with max ac on and once with regular ac selected.
The pk/blk wire has 12v to it.
The blk/yellow wire does not have 12v
The red wire has 12v
I cant see any splices on these wires.
This is good.
Not good. We have to get 12v here for it to work.
I am thinking 12v here should not be blocking the 12v getting through the "solid state A/C clutch solenoid control.
This wire goes to EEC pin 54 which on 5.0 and 3.8 engines provides the ground to pick the WOT A/C cutout relay.
I suspect the fuse blowing episode may have zapped the solid state circuit in the IRCM.
1. Unplug and leave unplugged the compressor clutch.
2. Start it up with the A/C on.
3. Put your test light between the positive battery post and IRCM pin 23 BK/Y wire.
4. If you have a light this may be the fuse blowing problem. Stop here I'll come up with a different plan.
5. IF NO LIGHT, jumper 12v to pin 23 BK/Y wire.
6. The fan should run.
7. If the fan runs, remove the 12v jumper from pin 23 BK/Y wire.
8. Jumper ground to pin 22 RED wire to see if that makes the fan run.
W/ the engine running I checked the circuit twice, once with max ac on and once with regular ac selected.
The pk/blk wire has 12v to it.
The blk/yellow wire does not have 12v
The PK/BLK better have battery its for the FUEL PUMP Pin 5 !!! Not the circuit you are having an issue with.
The BLK/Yellow is for the compressor clutch.
Ok here goes it
Fuse 17 feeds one side of the Cycling clutch switch. The battery comes from the panel control switch in the dash to the cycling clutch switch. The other side goes to pin 21 of the IRCM. The AC clutch gets its battery and ground from the IRCM. Ground from pin 16 and or 15 which are common. The battery comes from pin 23 of the IRCM. Pin 23 is interrupted by the ECM commanding it to do so with a WOT signal from PIN 54 of the ECM to pin 22 of the IRCM. So you shot that trouble correctly and the fuse held.
So when you were blowing fuses the first thing you should have dun was disconnect the plug from the CYCLING SWITCH and see if the fuse blew. Which you did. If it did not your next step should have been to disconnect the IRCM If the fuse did not blow your next step should have been the ac Compressor clutch which you did. But now that its work all bets are OFF
I would bet the diode was touching ground somewhere. Just a guess
The high pressure ac switch turns on the secondary fan. The sensor closes at a set pressure. The primary fan is controlled by the CTS. If you unplug the CTS the fan runs. Or if the vehicle reaches i THINK 223* the ecm commands on both fans. Well good luck and i hope it HOLDS
So if it acts up again we will start from scratch. Cant fix something that is working GOOD LUCK
Hopefully he checked the correct wire and just posted the wrong color code in his reply.
He will let us know.
WOOOOHOOOOOOOOOO!
Sorted it!!!!! I rechecked for foreign splices in the harness, like soft touch mentioned, and spied a black wire coming from the cycling switch on top of the accumulator. It was heavily wrapped and I missed it before. I snipped it and everything works again!!!!!!
freaking awesome...thanks for the help all.
I am curious to know where the other end of that wire is.
I will let you know tomorrow. it was over 100 degrees today, and I was melting. The wire runs across the cowl to the drivers side, so I expect it's part of that alarm BS. YOu should see all the splices in there. i will post a pic of it all. it is scary.
YES bad wiring by people that should be stocking SHELVES AT WALL MART. Good hope all is OK NOW. I bet the guy rah that wire to a toggle switch to operate the compressor CLUTCH???? WHEEEEEEEEEEEEEEEEEEEEEEEE!!!!
the black wire? Went to a ground. Aint that some .
Well that would be a circuit designed to blow a fuse.
it...spoke to soon. The car overheated on the way to work today, so I pulled over to see if i could find something. I then turned on the a/c and the fan came on, which cooled it down enuff(195) to get to work. Sooooo, the a/c is functioning properly, but the EEC aint gettin the word that yo, I am hot gimme some fan. I am looking at the wiring diagram's but cant figure out where the signal comes in at on the IRCM to turn the fan on. I am thinking it has to be the ECT sensor, but i did r2 it with a spare one.