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Topic: '88 --3.8 TBird Cooling (Read 7598 times) previous topic - next topic

'88 --3.8 TBird Cooling

Reply #30 –
sounds good,
the gray wire at the ign switch has 12v.
after the resistance of the wire has its intended effect, you have 5vac present at the input of the ivr.

using your own power source you will make both the fuel guage move.


you should be able to simply ground your temp guage wire out and it will peg out with a slow but smooth needle movement.  i would throw the 10ohm resistor in line with the ground leg as well for some degree of protection.

good luck, you came in leading us on to thinking you werent really able to do all the things you doing now but i am impressed.  good work and hope we can help nail this issue,, as old as it is it would be nice to be done with it.
like tom said, if you watch real close you will see the needle sorta twitch,,thats the AC going though stuff.

'88 --3.8 TBird Cooling

Reply #31 –
This likely might be one of my last necessary posts on this thread--because the problem appears solved!!! Earlier today, I had the cluster back out. I rotated the calibration screw back out about 1 1/2 complete turns--purely a guess. I also located the grey/yellow striped wire in the left connector for the cluster. Note --all the wires in the loom were striped except one black one which was also located in slot 12. There are actually 2 grey/yellow wires and I got a reading on the one located in position 12 (the smaller of the two). I connected an ohm meter to it and its terminus at the ignition and got nearly 9 ohms. I put the cluster back in and drove the car about 12+ miles, 8 of that on the interstate. Today is 90+ F here; sun out and high humidity. The info was: The temp gauge remained cold for about 5 minutes from the house and then slowly climbed to more than 1/3 of the operating range--about what it has always done long in the past. I topped the gas tank (1/2 gal) just to see where I could get the fuel needle to go. It now looks more realistic at the top of the pin points indicating full. This new place for it is less than it used to show (in the life of the car). After the interstate, I stopped in a lot and shut the engine off. 5 minutes later I restarted and watched the temp needle actually start at midpoint and then back down as I might expect it to since the fan would be running etc. It all seemed very normal to me. Above --I mentioned a black wire in the loom also tucked into slot 12. When I was reinstalling the cluster, the black wire revealed itself at a factory taping of the wires--the old tape fell off. The wire was cut off. At first I thought I had made a bad error in severing a wire while positioning the cluster. Not so----there was no further piece of wire found and it appears that the factory simply installed it that way---perhaps an unused option--who knows. It did confuse my testing to see that black wire in there. The pictures I include here show the car on the interstate, well into the trip (already gassed up again). #2 later in the garage at home after pulling in (engine off).

I thank you so much guys on this thread with your help!!!!!!!--without it I would not have succeded in making this repair--not to mention that I didnt spend a cent for the IVR repair!! Tom Renzo pretty much had this one pegged from his first comment--BRAVO TO YOU! What would cause the IVR to drift off accuracy-- just age?--meaning that it needs to recalibrated or something else changed the envelope of temp operation? I chose to BACK OUT the screw because it was obvious with the heater wire, the points are meant to float and open. Telling me perhaps they were not doing it because of too much forward tension on the lower arm. I can post more pictures --maybe for someone else's reference on this subject. This was the most puzzling and annoying issue I ever had with a vehicle. Our T-bird has always been well cared for and had little problems--so when this headache started about 6 years ago, I was determined to get to the bottom of it. Unfortunately, a bunch of engine components including a fan clutch and water pump were part of the list. I'm happy anyway as they would likely needed to be replaced at some point.

JR

'88 --3.8 TBird Cooling

Reply #32 –
Good job and as i stated i have replaced many of those units with electronic ones. They go bad and cause all the gauges to read very high!!
I spend money I don't have, To build  cars I don't need, To impress people I don't know

HAVE YOU DRIVEN A FORD LATELY!!

'88 --3.8 TBird Cooling

Reply #33 –
Yeah I just saw your post jcassity---again much gratitude to all on this as every post including the wiring diagram was essential to my understanding of this matter.  Fortunately, I have previously learned how to read wiring schematics and that was a tremendous help here in understanding this temp operation.  These pics show the gauges before the work--with the temp gauge short of H--and would go closely there.  Also the fuel gauge minus 10 gallons.  The IVR shown.

'88 --3.8 TBird Cooling

Reply #34 –
Thanks so much TOM!!!!

'88 --3.8 TBird Cooling

Reply #35 –
good calibration guess, thought that might cure it if the gray wire had good resitivity.  9ohms is a good reading in my opinion.
time to put this dog to rest.. *SOLVED*

'88 --3.8 TBird Cooling

Reply #36 –
Just a FYI for anyone else--I found this on a Google search--a Mustang forum.  This is a do it yourself solid state IVR but the one shown I believe is meant for a '60s Mustang.  I am sure an electronics tech here could reconfigure.  The 3rd picture leaves the unit to be figured for hook up.  The parts cost less than $10.  Since our units have snap connection to the cluster--I suspect someone could come up with the answer on both counts:  Correct calculation and parts and 2) hook up.

'88 --3.8 TBird Cooling

Reply #37 –
And maybe finally---an EBAY seller in Florida selling the IVR fitting the '88 T-BIRD.    Note my pics on the DIY IVR above were placed out of sinc.

'88 --3.8 TBird Cooling

Reply #38 –
to do this, a person would have to ommit the resistance wire from the ignition switch so 12v arrives at the coverted ivr.
 

'88 --3.8 TBird Cooling

Reply #39 –
i have a forum in electrical tech called the mysterious instrument cluster problem something of that nature any way seeing that you have taken to fixing instrument clusters, some aid would be much appreciated if you can check it out thanks