1985 Fiero Engine Wiring Questions (Page 1/2)
82-T/A [At Work] JUL 01, 07:16 PM
Hey guys, I've removed the engine wiring harness from my daughter's Fiero, 1985 Fiero 2m4 SE. I'm going to do the electrical for her, and I've started to remove the old electrical tape and plastic sleeves, etc. My goal is to replace any broken connectors, check the entire harness for any kinks or cuts in the wiring (I found two) and clean it up and tape it all back up. I'm actually very impressed at how easily it came out, and how simple the connections were.


So, couple of questions:

1 - What is the easiest way to clean this wiring harness. I want to completely clean all the wiring and make it "like new" before I bundle it up again and re-tape it. Question is, what kind of cleaning products can I use... just dish soap? Can I let it soak in a bucket? I don't want to damage the wiring. I would let it completely dry inside (there would be several months before it gets used).

2 - Where can I buy that original aluminum (fabric-backed) tape that was used as heat shielding tape?

3 - I found ONE plug that I thought was totally weird. It's attached right next to the Fan Switch sensor. You can see in the picture here... there's the normal fan switch sensor, and then it's a little red connector that looks almost identical to the temperature sending unit sensor that's meant for the temperature gauge on the dash. Like... it's an identical plug.


This images is larger than 153600 bytes. Click to view.


Keep in mind, I know this isn't the temperature gauge sending unit connector, because that's over here:

This images is larger than 153600 bytes. Click to view.


Any idea? My thought is maybe the harness has two connectors, in case GM decided to use a different sensor for the fan switch? I really don't know...

Thanks!

[This message has been edited by 82-T/A [At Work] (edited 07-01-2024).]

PhatMax JUL 01, 07:53 PM
If I remember, you have a 4cyl ? Here’s a pic of my 85 V6.
Check with Wirecare.com for wire covering. The sliver stuff isn’t cheap. I use the stuff that’s good up to 1200 deg.
Hope this helps
PhatMax JUL 01, 08:00 PM
Forgot, as far as cleaning…DONT USE WATER. I used denatured alcohol, leaves no residue.
For the connectors here’s what I did.
Use good cloth pipe cleaners you get from a smoke shop…. Get some Tarnex, dip pipe cleaner in , scrub the connector contacts. Don’t let dry, use the alcohol and flood the connector, I use a small bottle with a small tip. After that blast the connector with high pressure air.
Get some Deoxit, spray contacts…should be good to go ! Did my whole harness that way…..not a single problem.
I did have to replace two connector bodies as they were cooked.
82-T/A [At Work] JUL 01, 08:37 PM

quote
Originally posted by PhatMax:

If I remember, you have a 4cyl ? Here’s a pic of my 85 V6.
Check with Wirecare.com for wire covering. The sliver stuff isn’t cheap. I use the stuff that’s good up to 1200 deg.
Hope this helps



Oh man, this is great! What a site! Thank you... I had no idea everything was in one place, I appreciate it!!! And yeah, it is a 4 cyl, just updated my original post, totally forgot to mention that.



quote
Originally posted by PhatMax:

Forgot, as far as cleaning…DONT USE WATER. I used denatured alcohol, leaves no residue.
For the connectors here’s what I did.
Use good cloth pipe cleaners you get from a smoke shop…. Get some Tarnex, dip pipe cleaner in , scrub the connector contacts. Don’t let dry, use the alcohol and flood the connector, I use a small bottle with a small tip. After that blast the connector with high pressure air.
Get some Deoxit, spray contacts…should be good to go ! Did my whole harness that way…..not a single problem.
I did have to replace two connector bodies as they were cooked.



Ok, how come no water? Is there something particularly bad about it? (quietly goes downstairs and dumps out the bucket where 80% of the wiring harness is soaking in)


I still don't know what that weird red connector is... but I'm going to search the service manual... I don't remember seeing it anywhere in there though. So strange...


Thanks!!!
theogre JUL 01, 09:34 PM
Cleaning, worse soaking, in water then wiring will "suck" water inside then rot.

Alcohol is cheap but need > 90% or have too much water.
Plastic Safe Electric cleaner w/o lube from CRC etc works on wire insulation etc. Ones w/ lube works on pins in plugs & other metal parts.

Likely need Bulb Grease etc to reapply to C500, relay sockets, etc. already covered here... http://www.fiero.nl/forum/Forum2/HTML/147737.html

Little red plug was for 2 speed rad fan but only 84 actually use that. Is just an artifact that GM miss to delete from engine wiring. Even 87 duke having way different engine wiring still have this orphan plug.

------------------
Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should.
(Jurassic Park)

The Ogre's Fiero Cave

[This message has been edited by theogre (edited 07-01-2024).]

82-T/A [At Work] JUL 02, 07:43 AM

quote
Originally posted by theogre:

Cleaning, worse soaking, in water then wiring will "suck" water inside then rot.

Alcohol is cheap but need > 90% or have too much water.
Plastic Safe Electric cleaner w/o lube from CRC etc works on wire insulation etc. Ones w/ lube works on pins in plugs & other metal parts.

Likely need Bulb Grease etc to reapply to C500, relay sockets, etc. already covered here... http://www.fiero.nl/forum/Forum2/HTML/147737.html

Little red plug was for 2 speed rad fan but only 84 actually use that. Is just an artifact that GM miss to delete from engine wiring. Even 87 duke having way different engine wiring still have this orphan plug.




Thanks Ogre, I appreciate it. I was hoping someone was going to say that the little red plug is the connector for the super-rare CURS or DRS system that was installed only in the 1985 model year... but alas, that's kind of funny. For the sake of my curiosity... does it do anything, as in, does the computer or fan actually do anything with it, such that I could actually install a 2-speed fan *(and would that benefit anything at all)? Last question, is there any reason why I should keep it there, or can I carefully excise it from the rest of the harness? I see that it shares one of the wires with the fan switch.

Side Note: I scoured the 85 and 86 service manuals last night, and saw no mention of the plug... so I appreciate you mentioning it here. It was eating at me... haha...

[This message has been edited by 82-T/A [At Work] (edited 07-02-2024).]

theogre JUL 02, 10:57 AM
1 wire is same pin as other fan switch in C500. Other is another pin in C500.
Could cut 1 wire @ C500 & completely remove the other to loose that plug.

Likely second wire end @ C500 Or maybe somewhere in cabin depending on cabin wiring.
84-86 duke (& all v6) ECM knows nothing of rad fan.

Can't easily add 2 speed fan & require relay. Most times can't even get the needed switch or if block/head had extra hole to put it in.

See https://web.archive.org/web.../~fierocave/fans.htm
82-T/A [At Work] JUL 02, 03:03 PM

quote
Originally posted by theogre:

1 wire is same pin as other fan switch in C500. Other is another pin in C500.
Could cut 1 wire @ C500 & completely remove the other to loose that plug.

Likely second wire end @ C500 Or maybe somewhere in cabin depending on cabin wiring.
84-86 duke (& all v6) ECM knows nothing of rad fan.

Can't easily add 2 speed fan & require relay. Most times can't even get the needed switch or if block/head had extra hole to put it in.

See https://web.archive.org/web.../~fierocave/fans.htm




I definitely don't need a 4th sensor in the cyl head to deal with temperature... so I'll remove it. Thanks Ogre.
82-T/A [At Work] JUL 04, 08:00 AM
I found a section of wire... the thicker gage starter wire (not the really thick one that goes directly to the battery) where the two leads coming off of it are burnt. Not a fire, to be sure, but it just looks like they've ben cooked and the rubber insulator has cracked. It's about a 5" section where it likely passed by the exhaust manifold. I had no electrical issues that I could tell, and the car had plenty of power. Can I simply tape this up, or do I need to cut out this entire section? I'd planned to completely wrap and insulate this wire. The wire itself seems to be OK, it's just that I can see the copper in a couple of places because the rubber split. The whole rest of the wire is OK and I feel like making a splice is going to be much worse... thoughts?
theogre JUL 04, 08:27 AM
Few things have heavier wire then others...
Starter & Starter to AT Neutral Switch.
Alt.
1 Ground from engine to left side frame.

IF any are "Cooked" is very likely has problems besides being too close to the exhaust.

Example: Grounds to frame cooked can be bad battery cable & using them as side/sneak path when starting dumping 150+ Amps running the starter motor.

Just the Starter Solenoid pulls 30+ Amps can cook damage/deffective wiring.