need advice wiring issues

[jeffwilson34]

The black tar-like stuff is a weatherproofing Dielectric grease compound.  It should be there.  You'll find it in most of your relays and heavy voltage connections.  Before completing the assembly, get yourself some tubes of dielectric grease compound and liberally fill all the terminal cavities and around the outside surfaces of the terminal block to prevent water shortages.

i thought that was what it was, but it seems to be messing up the connections.   
Is there a place to buy new pins that fit in the blocks?  I have some for the connectors on my corvette but they are not the same type and the place I got the Vette pins does  not have any that match the ones in the Fiero.
I think the reason the  different wiring and and things is Pontiac used whatever off the shelf parts were available when they were making the Fiero due to the limited budget they had from GM who did not want another GM product to possible pull sales from their Cash Cow the Corvette and the Fiero could have easily pulled some Vette customers if it had a bit more power.    Having owned an 86 Vette and an 87 V6 Fiero GT  I can speak from experience and say that the Fiero was a better handling and smoother ridding car.    The vette had much more power and could outrun the Fiero on a interstate, (although my 87 was doing fair in keeping up with a Vette until somewhere above 120MPH the wind caused the headlight doors to pop open like air brakes  which in turn almost caused a change of underwear till I realized what happened) but if you were to take a stock 87GT 5 speed and stock Base 87 Vette with that crap 4+3 manual / automatic hybrid transmission the Vette had at that time  to a road like the dragon and do timed runs I would put my money on the Fiero.

[TopNotch]

The black gunk could be contaminated and/or too dried out to allow proper connections. Spray all connectors thoroughly with WD-40, and re-connect while still "wet" with it. WD-40 is an excellent contact cleaner. Sometimes you can even "fix" an assumed bad ignition module just by removing the connectors, spraying them, and replacing them.
Back in the days when slot car racing was popular, sometimes racers would spray the commutators of their electric motors with WD-40 to make their cars go faster.

[jeffwilson34]

I will give that a try.
Man I remember slot car racing, I never saw anyone around here using wd40
we did a lot of things to get that added edge, from rewinding the armature, using magnets as weight to keep the car from sliding up the banked track, and even adding capacitors  to provide power if the brushes  lost contact at a bad part of the track.       
I think at one time I had more money invested in  my slot cars than my real car.

[jeffwilson34]

I have came to the concolusion that the only way I am going to be able to fix this and do a halfway good job is to tackle one wire or problem at a time.  I am going to purchase some of the cheap spade male/female connectors and get it all correct and working then go back and get some of the gold plated connectors with shrink wrap already on them and replace the cheap ones.
This will bypass the C500 and whomever gets it after I sell it will hate me but I plan on leaving a note explaining why.

I will be the 1st to admit I am not the best at wiring things  and have a coup
le questions.
DO the gauges has a HOT (positive) connection at all times an use the ground as a signal?
Does anyone know the color of the wire coming from the key switch that engages the starter? On the same system what color is the wire going to the solenoid and where does it come from?  I found a thicker red wire with a round terminal tucked away in the wrapping that also contained the O2 sensor. It will not reach the starter and has no power on it nor is it grounded. 

I can get most things running except the gauges, the heater stays on hot, I can not get the AC compressor to enguage the clutch but I can get hear the cruise control clicking when power is applied to 3 different wires.   I have them tied off for now marked as Cruise control.

I can not get over how smooth it runs and the transmission shifts perfect. It will sit and idle a bit high when 1st started cold but after a few minutes the idle slows down to a normal slow idle.
I drove her around tonight and according to the GPS i put 125 miles on her and averaged 32 MPG and got up to over 100 MPH (this was on a private road that the state gave to a farmer when they took part of land for a new road)

[jeffwilson34]

I am slowly making progress.
Just got back from a nice long drive out in some old small country roads
I have the oil pressure, gauge working, the charging idiot light now works, the speedometer and odometer is working, radio is working. all the lights other than the back up lights work.  The gas gauge even seems to be giving correct information. The cooling fan turns itself off and on as needed.
What is not working is the Tachometer, and temp gauge and starting with the key.
I can get an aftermarket temp gauge and tachometer if needed but  would really like to fix it so it starts with the key

Anyone have any experience tearing the dash apart to get to the key switch?  If all else fails I could run a fused hot wire from the start position on the key switch down through the dash and tie into the current push button start.

I am going to take tomorrow and rebuild the bad headlight motor and bleed the breaks because they are a bit too spongy for my liking.

I know if and when I sell it, spmewhere down the kine someone will hate when they see how it is repaired.       

[Fierofool]

Automotive electronics isn't my bag, but a suggestion on the tach is to check out the tach filter near the ignition coil.  It's a little gray cylinder about the size of an old TNT firecracker.  It may be missing or unplugged or just plain bad. 

It's been a while since getting into an ignition switch swap, so I won't try to give you wrong information. 

To test the temp gauge, go to the engine bay and unplug the harness at the corner of the head, just upper left of the number 5 cylinder.  It should be a green wire and a green wire with tracer.  The sending unit should have a round head with a split in one side of it.

With the ignition on, insert a probe (paper clip) into one of the female terminals and bump it onto the engine block.  Either the gauge will move or the idiot temp light will illuminate.  Now, put the probe into the other female terminal and bump against the block again, and the one that didn't work the first time should work this time.  One of the circuits is for the gauge, the other is for the light.  That will tell you if your circuit is good or bad. 

To test the sending unit, let the engine be cold.  Unplug the harness and using a multimeter set to ohms, put the negative probe against the base and the positive against one of the male terminals.  One of them may not give a reading.  I think it will be the light circuit.  Try the other and compare your reading with the chart listed here:

http://www.gafiero.org/bbs/index.php?topic=641.msg4644#msg4644

[f85gtron]

To answer you're earlier question, the guage signals are to ground. In other words, positive to the guages from ignition, Then they are grounded through the sender. As Fierofool alluded too, it's just a matter of grounding the leads to test guage operation. Hope this helps.

[jeffwilson34]

so the fact that the gas gauge, oil pressure, and speedometer work should indicate power is flowing to the panel, correct?  The battery light came on when I grounded out the wire that goes to it so I think it is working.
Now I need to locate the tach and Temp wires and I am in almost finished.

The starter has me lost because I think the switch may be defective.   I may put a secret push button starter switch behind the center console

Another thing that has me curious in the hidden switch to activate the engine fan.   The fan works as it should and comes on and goes off on its own

[Raydar]

...

The starter has me lost because I think the switch may be defective.   I may put a secret push button starter switch behind the center console

Depending upon the transmission type, there will either be a large yellow (or large purple) wire under the dash. 12 volts to that wire should activate the starter. If it's a manual, that wire will go through a switch on the clutch pedal. Maybe even change colors there. If it's an automatic, it'll go through the P/N switch on the trans.

I apologize for the redundancy, if you already know all of this.

[jeffwilson34]

actually the large yellow at the switch is a great help.
If I can trace that one back as far as possible then tie into the wire that is tied into the solenoid   I can work with that till I have time to hit the P/N in the transmission.   (automatic)

[Raydar]

The yellow wire goes straight to C500 (the connector in the corner of the engine compartment, next to the battery.)
It goes through that connector to the P/N switch on the tranny. From the P/N switch, it's a big purple wire to the starter solenoid.

[jeffwilson34]

  IT LIVES AGAIN. 
Not perfect and still has a few things to work on but I feel safe driving it.
It had been sitting under a tarp when I was not working on it with my chair, work lights, etc... 
Today I drove it round the block, pulled into the drive, and then put everything that had been sitting there with it like it was on life support or something  up.   
After everything was put up, I got in and fired it up and took off down the road again.   I swear two of my neighbors gave me the thumbs up and clapped when I drove by.

I gave it a good little test run

Thanks to all who have helped.
Finally today I got most everything working.
Starts with the key switch,  not a jerry rigged push button.
Tach works
fuel gauge works
Oil pressure gauge works
speedometer  works and the speed it says agrees with my GPS
All lights work  *will need new headlight motors, I tore one down to rebuild and found that the brushes that supply power to the armature were missing and somehow it had been working off just the copper making contact with the armature.
There is a local guy with a set of 88 motors and assemblies but no wiring.   from my research on the differences It appears I need the control box in order for those to work.
Still Can not get the Temp Guage or light to work but the fan does kick on when it sits running a bit.
I have not even started on the cruise control or AC    but I am happy for now.

I did finally end up bypassing the C500 and currently the connections are male / female spade connectors because I found it easier to use them to change wire combinations.    When all is finished they will be soldered and double covered with shrink wrap.

[Fierofool]

Now that you've gone through all the effort to get things worked out and fixed, keep the car and enjoy it rather than selling it.  And be sure you have fusible links on the proper wires coming off the C500.  And come join us for Run For The Hills.

[jeffwilson34]

from what I can tell all the fuesable links are in place.
I think the owner that hacked the harness did so because of a bad fuesable link.
Lots of issues I had originally went away when I installed the new distribution block with new (used) fuesable links.

If I have to I can get a cheap TEMP gauge that the probe is inserted into the radiator by removing the hose and use it till I have more time to track down the reason the onboard ones does not work.
Still have a few more things that need done like bleed the breaks because they feel spongy,   Find 2 good headlight motors  I thought I had found a set locally but they were off a 1988 GT.   fix the AC, find a luggage rack and remove the wing.  or fix the holes where the luggage rack was attached and paint the wing.

At the moment the wiring harness looks like crap but that is temporary.  I do not want to tidy  it up till I have everything fixed.  I have shrink wrap around all the connections that have power or are grounded. and electrical tape on top of any connector that is nit connected to anything.     My plan is to fix all the wires with solder and heat shrink then make a waterproof enclosure from a radioshack project box and some clear sealent I have left over from repairing a fish tank.
I plan on making it to the run to the hills, barring any unforeseen events/

[Raydar]

That's the quickest I have ever seen anyone go from "eff this" to "It lives!"
Congrats on your diligence and resourcefulness.