I have been reading up on how to fix the pegging temp gauge problem (here: http://www.fierosails.com/tempgage.html) and am left with two questions:

1: the info in the article is referencing 84 and 88 models; has anyone done this exact fix to 85-87 2.8s with success?

2: the plastic connector on my temp sensor wiring loom has completely melted away (as most do) and although I can find out which wire is for the idiot light and which is for the gauge needle, I cannot find any references to which pins do what on the actual sensor; can anyone tell me which pin on the sensor is for the idiot light and which pin is for the gauge needle?
(the reason I ask is because I'm supposed to swap the wires... but I can't swap them if I don't know which orientation they were in to begin with )

Thanks in advance! I'll be completing the wire swap this weekend.

Yes it works for 84, 85, 86, 87, 88. Both the 2.5 and 2.8 engines

The temperature gauge sending unit has two functions. The wire that connects to the pin that is AWAY from the side notch is for the gauge. The wire that is close to the side notch is for the TEMP light (yes your Fiero has one).



AFTER COMPLETING THE DASH WIRE SWAP

Turn the key on but leave the engine off. Ground one of the wires. Then try the other. One should light the temp light. The other should make the temp gauge (or just pivot in your case) move. Then just make sure the wires are on the correct pins so the two devices work correctly.
The plastic shell on the temperature gauge sender connector tends to get brittle and fall apart. New plastic shells can be obtained from Rodney Dickman for $7.50 delivered to your mailbox. Damn cheap if you ask me.

http://rodneydickman.com/ca...h=21&products_id=174

[This message has been edited by phonedawgz (edited 05-07-2014).]

quote Originally posted by phonedawgz: The wire that connects to the pin that is AWAY from the side notch is for the gauge. The wire that is close to the side notch is for the TEMP light (yes your Fiero has one).

So just to clarify: the above orientation you've listed needs to be swapped along with the wire swap at the dash?
The reason I ask is because I have a friend who says he's only ever done the swap at the dash and never at the sensor.

Thanks!

If only one end is swapped the gauge and light won't work.

When I build engine swap harnesses I build the swap into them so only the dash end is needed.

I don't identify the wires by color but instead by testing. So if the dash swap was preformed the wire that lights the light/activates the gauge swaps but will still give you the correct results.

quote Originally posted by phonedawgz: The wire that connects to the pin that is AWAY from the side notch is for the gauge. The wire that is close to the side notch is for the TEMP light (yes your Fiero has one).

This is how the sender is built.

[This message has been edited by phonedawgz (edited 05-07-2014).]

So I've done the wire swap at the dash:
- Light green wire from 11 has been moved to 13
- Dark green wire from 13 has been moved to 11

Went to swap the wires at the temp sensor and was grounding them (as people say to do) to find out which wire controls what.
I found the gauge wire easy enough (the gauge pegged as usual).
But when I grounded the idiot light, it didn't light up! The bulb has been tested as good, so why is the idiot light not turning on when it's grounded?

quote Originally posted by Enix: ... But when I grounded the idiot light, it didn't light up! The bulb has been tested as good, so why is the idiot light not turning on when it's grounded?

Just for closure (and for historical reference in case anyone else faces this), some of the traces on the printed circuit board (on the rear of the instrument panel) were broken. The plastic film had separated in the lower corner behind the tach and severed the traces for the temp warning light and the e-brake light. I swapped out the circuit board and both lights work fine now.

Enis I am at the point where the describe the no light. Will go home now and pull the dash out again and check that dang flexi circuit board..

Thanks..

.

------------------
Mark
' 85 2m6 3.4PR
In the Great Northwest!

quote Originally posted by NW-Fiero: Enis I am at the point where the describe the no light. Will go home now and pull the dash out again and check that dang flexi circuit board..

My friend supplied me with the extra circuit board and it too had started to separate in the exact same spot (the lower corner below the tach), so it must be a common place for these to deteriorate. We just taped the new one back together with electrical tape because the copper traces weren't broken.