All of the pinout diagrams I have found for my 1988 GT show a Tan/Blk wire in the C203 "A" position (Shift light). Mine has a gray wire there. Can someone tell me what circuit this is?

Thanks.

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1988 GT, 5-speed, white, beechwood leather, 3.4 DOHC 6-speed installation in process. Really. I am working on it.

I notice that colors vary a bit on these connectors, I would assume its still your upshift light if its in that position.

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My understanding was the V6's didn't get the upshift light. At least mine has never worked. Maybe the wiring is there but not connected to the '88 computer? I have an upshift output on my swap 9396 computer and figured I'd hook it up, if possible.

Anyone else?

[This message has been edited by sspeedstreet (edited 11-21-2007).]

^^^

My 88 GT did not have the wiring for the shift light; neither did my Formula.

...just meter the wire out to the connection (C3/1) on the dash that is suppose to be the shift light wire. If it shows continuity, then it is the shift light wire. Or, go back the other way (if still possible) and see where is was connected to the ECM.

Pinouts are usually correct - wire colors not always, but still verify with a meter.

Did the '88 GT's come with a upshift light from the factory? My '88 GT does not have one.

I have no wire in my C203 position A on my 5 speed 88GT. I guess it is safe to assume it doesn't exist. It's a shame, because I went through the trouble of wiring the shift light for my 3.4 DOHC, but I never checked the CAR for the wire till now... We really need a resourse somewhere that has all the correct pinouts for all configurations and years as they were produced. It's actually quite difficult to find a pinout for the C500 for an 84, Unless you happen to have the factory manual. Little resourses like that are a boon when you are doing an engine swap. Maybe I will have to make it a personal mission.

ya my 88 4 cyl; had no wire in a and my shift light was the color that it said but was not in the right spot

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quote Originally posted by Mickey_Moose: ...just meter the wire out to the connection (C3/1) on the dash that is suppose to be the shift light wire. If it shows continuity, then it is the shift light wire. Or, go back the other way (if still possible) and see where is was connected to the ECM. Pinouts are usually correct - wire colors not always, but still verify with a meter.

It's all still open while I chase down the last few unconnected wires. You've pointed out the obvious answer; chase the wire and see where it goes. But it does seem to open the question: There is definitely a grey wire in the "A" slot. A couple others here say there's no wire at all in their's. I'll post what I find when I trace it.

according to the 88 factory service manual:

there is no shift light on the 2.8l motor

the 2.5l motor however, shows the shift light connected. From C3/1 on the gages to C203/P to ECM C1/7 (TAN/BLK wire).

I also do know that in 88, the cars are not always as they are suppose to be. Towards the end of production things where left undone (my 88 never had the front compartment switch installed (the wiring was tucked up inside the harness)). So could the wire be for something that was suppose to happen or in the early production cars - anything is possible.

Of course this wire could have been added by a previous owner, but it's odd that someone would install the pins on the wire and insert them into the plug. That is only something that I would do because I am weird (or anal) when it comes to that kind of stuff, most people just run the wire.

quote Originally posted by Fierobsessed: We really need a resourse somewhere that has all the correct pinouts for all configurations and years as they were produced. It's actually quite difficult to find a pinout for the C500 for an 84, Unless you happen to have the factory manual.

Myself I would prefer to buy the manual for all my cars (they all have one) - sure they are not cheap, but they are well worth it in case you have to look up some odd stupid little item. Again, that is just me

[This message has been edited by Mickey_Moose (edited 11-22-2007).]

quote Originally posted by Mickey_Moose: I also do know that in 88, the cars are not always as they are suppose to be. Towards the end of production things where left undone (my 88 never had the front compartment switch installed (the wiring was tucked up inside the harness)).

On that front compartment switch, I wanted to add the light to my front compartment. There was already a wire for it in the C100 (cabin side), but nothing else. I was looking at an '85 here in town to see where the pin switch was supposed to be mounted. The owner said it didn't have the light either, but his had the switch, all the wiring and the bulb holder. But no bulb and no bracket to hold it.

Yeah, you never know what you'll find.

OK, here's proof I have no pride. I put the gray wire in there. Been so long since I did it I forgot. It's a 5V reference for the A/C pressure sensor added in the front compartment.

Well, I've been working for a "factory installed" look. Fooled me, anyway.

Now look away while I shrink from view.