need advice wiring issues

[jeffwilson34]

I am having a rough time with some wiring issues.   
The car is an 86SE with the 4cyl.   I  bought it and it ran fine but I discovered a nightmare wiring jumble that whomever   did it is lucky he did not burn the car up.   The wiring block  (c500) had several wires cut off  and then spliced into other   wires that did  not match color and he had cut the wires at the connectors that I could not see the original color, I got a c500 and wiring harness from Tha Driver off a parts car. (I also want to thank him for getting it to me so fast)

I have been working on repairing the wiring as I am able (I have a very bad back and have no feeling in my right side)
I can work about an hour at a time before having to stop.     I have found a couple different wiring diagrams online    and the colors or pin location appears to change from year to year and even car to car.

I am trying to make sure I have the connections are correct before doing a final splice with solder and shrink wrap.
I have been able to get it running good and the battery charging   although I am going to replace the alternator because it sounds like it has bad bearings.  The lights all work but non of the gauges work
 Here are my problems and questions.

1. what is the easiest way to remove the alternator from a 4cyl
2. it will not start with the switch, the previous owner had rigged a push button starter by attaching a wire to the solenoid and running it inside,  Where does the wire that is supposed to attach to the solenoid come from?
3.  I have several wires from   the harness that do not match up with anything.  Does anyone with an 86se 4cyl  wiring diagram,  Mt repair manual does not have one.
4 This one is from before I started working on the wiring.     The left headlight went up on its own and would not go down.   I put it down manually and it stayed down a while then went up on its own again.   The motor does not keep running like when the gears are worn out and the light does not come on till I turn it on.    I am thinking its most likely a relay but no idea which.     (this is a non issue right now  just something to repair later)
5. Any members in the East Tennessee area that can work on this wanna make some extra cash.

Thanks in advance.
6. If all else fails anyone want to buy an 86se that runs good.  MAKE OFFER

[Fierofool]

Jeff, I didn't realize your car was a 4 cylinder.  The stuff you got form Paul was from a V6.  There may be a few wiring differences.  Let me check the Helms Manuals we have to see what schematics are there.  It will be at least Sunday afternoon before I will have time.

To remove the alternator from an Automatic, at least on a V6, you must remove the right wheel and wheel well liner skirt, loosen the tie rod end and work the alternator out through the wheel well.  I don't know if the 4-cylinder is any different. 

[f85gtron]

The c500 block pinout changed a couple times through the years and is also different for autos vs manuals....i think. Something about the starter wire being in a different location and some ac stuff. If Fierofool doesn't get you what you need, i might be able to track something down.

[f85gtron]

Here's one:


And another:

[Tha Driver]

Jeff, I didn't realize your car was a 4 cylinder.  The stuff you got form Paul was from a V6.  There may be a few wiring differences.  Let me check the Helms Manuals we have to see what schematics are there.  It will be at least Sunday afternoon before I will have time.

The C-500 & tailight/body harness was from the '86 se, the engine harness plug (that goes into the c-500) was from an '88 base coupe 4 cyl.
I *think* it will work, but I'm not 100% sure...
~ Paul
aka "Tha Driver"

Custom Fiberglass Parts

[f85gtron]

Looks like you'll just have to repin the harness to match what's on the car.

[TopNotch]

Jeff, I didn't realize your car was a 4 cylinder.  The stuff you got form Paul was from a V6.  There may be a few wiring differences.  Let me check the Helms Manuals we have to see what schematics are there.  It will be at least Sunday afternoon before I will have time.

The C-500 & tailight/body harness was from the '86 se, the engine harness plug (that goes into the c-500) was from an '88 base coupe 4 cyl.
I *think* it will work, but I'm not 100% sure...
~ Paul
aka "Tha Driver"

Custom Fiberglass Parts

The 88 4-cylinder has DIS ignition, and the 86 4-cylinder has a distributor. So the engine harness is going to be different.

[f85gtron]

Here's another one attached.....

[Fierofool]

The 86 year models had just about everything Fiero ever offered.  Notchback, Fastback, V6, 4-cylinder, 4-speed Muncie, 5-speed Isuzu, 5-speed Getrag, and of course the automatic.  Wiring harnesses vary between Fastback and Notchback bodies.  They also vary between 4 and 6 cylinder vehicles, and manual and automatic vehicles.  That's probably why you're seeing some big differences in wiring schematics.

I tried scanning the Helms Manual but I can't get it into my scanner well enough to scan the full page.  Here's a link to 86 wiring schematics.  If you click on an image, you'll get a closer view.  Then to the right, click on View Image.  You might be able to print it out or save it to file. 

https://www.google.com/search?q=86+fiero+wiring+diagram&tbm=isch&imgil=xz--XlqiRE9mjM%253A%253BcpU5LBt4l-7GLM%253Bhttp%25253A%25252F%25252Fwww.fixya.com%25252Fcars%25252Ft5202181-need_wiring_diagram_1986&source=iu&pf=m&fir=xz--XlqiRE9mjM%253A%252CcpU5LBt4l-7GLM%252C_&biw=1280&bih=889&usg=__7bd1opVfQ00RLoVfEGXzuu3DXQs%3D&ved=0CDgQyjdqFQoTCPb4idrHnMcCFcfMgAodrGwDow&ei=gZLHVba0JseZgwSs2Y2YCg#imgrc=_&usg=__7bd1opVfQ00RLoVfEGXzuu3DXQs%3D

[jeffwilson34]

thank all of you guys again.
I took a break on working on it today and plan on starting back tomorrow

[jeffwilson34]

  Anyone want to buy a Fiero?   $1100 Firm 86SE 4cyl  Red, good body  (sans wing looks like a spray can paint job. and luggage rack removed from trunk)  almost new tires, Premium Black GT style wheels.
   I have worked 3 days trying to get this thing together right. I am ready to throw in the towel and sell it. I have tried several different wiring diagrams and non seem to match what is in this car.  Someone before me had rigged the harness. I noticed they had completely bypassed the c500 on several connections so I have no idea what is supposed to go where.   There are several green wires that are the same color  as well as 3 white ones. I think at the  moment I have some of those wrong.   Tonight I was getting close because more things are working correctly,  BUT I screwed my back up again and had to sit on the grass outside for 3 hours before I could get in the house.
  It will start and run fine, (have to jump the starter solenoid with a push button inside, it was was like that when I bought it )
  Issues as of right now.
1. non of the gauges work  (the did work at one point so I must have screwed something up)
2.  will not start unless key is on
3.  headlights work  (one needs new gears that I have) 
4. front parking, emergency and signal lights all work
5. left rear lights work
6. 3rd brake light works
7. Right rear lights do not work (bulbs are fine, ground is good  lights work with a hot jumper wire)
8. Radio will not come on, (works when a hot jumper wire is touched to its fuse, The clock does keep time and presets stay until battery is unhooked so it is getting power to the always hot section)
9. dash illumination lights work fine
10. windows work when key is on 
11. Testing for power at the fuse box shows only a few fuses have power with key on or off.  ( I am thinking there may be a fuseable link I am missing somewhere blown)
12. Drives fine an transmission works great.
13.  It idles good.
14.  The alternator works good and multimeter shows 13.6V at battery when running.
15. I have no idea about the AC because the belt was off when I got it but I doubt it works
16. The cooling fan was rigged with a switch when I bought it but I did trigger it to come on at the c500 at one time so its wires must still be good just and it may actually work but without a temperature light or gauge I do not want to let it run without the fan on.   The engine and transmission are the only things that work right.
18. Needs headliner

[Roger]

Patience Grasshopper.

You have made great strides in your repair quest.
There are times when we all must back away and reflect to see this.
Do not dwell on it at this time. Relax and lighten your heart.
Solutions will come to you when you least expect it and you will rise
above this disappointment.
The learning process on this addiction affects us all and you are not alone.
We have all been there.
We are proud of your accomplishments and you must realize what you have learned.
Some day we will need to call on your expertise and be grateful.
Once you have everything working as it should you will be glad you did not sell
the thing that sooner or later drives us all to madness.

[jeffwilson34]

well I had a friend come drop by today and he looked at it and got to probing wires for continuity through the block.
Turns out the C500 block is not connecting at some of the pins others have weak connections that will not handle the load of my test light which is a normal 1157 bulb  The voltmeter shows power at 12-13 volts and it will turn on an led 1157 bulb but fails with the normal bulb.   My original c500 had something that looked like black tar all in it. The new one I got had some but not as bad as my original.   I used one of the original plugs instead of the one sent me because the wire colors were different and it had a couple empty slots in different places and the c500 pins matched with my plug. I tried cleaning it out with everything from electrical  contact cleaner, brake cleaner, and various other things.
It looks clean but the tar seems to grow back every day and pins that were clean one day and dirty the next.   This may be the reason for some of the bypassed connections   that were made before i got it.   We were able to get the rear lights working by bypassing the c500.     
I am going to take a break till Monday.    I still need to get the gauges working.   I may try and find the wires that work them and bypass the the c500 on those also.     
The radio has me confused because it will power on when I apply a jumper wire to one of the green wires at the c500.   But it should get power from the switch which does get power and works the windows and turn signals.
No diagrams I have saw for the c500 list the radio.  Why would the power for it run from under the dash back through the back around the engine compartment and then back under the dash?
Can any one give me some pointers on the wiring of the tach, temp gauge and light, voltage light and gauge. and speedometer.     If it comes down to it I guess I could run new wires to them.   If I do not sell it I may end up just going and buying several spools of wire and making a custom harness  working one system at a time.

[f85gtron]

The sensors run through the bulkhead where the ecm is and connect again under your elbow (when in the driver's seat) at the connector just below the ecm @ C203. From there, they run along the center hump to the dash.

[Fierofool]

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.