[Alan F]

Man, I am PO'd! I was attempting to install the replacement engine wiring harness, that I purchased over a year ago, on my '72 GMC Sprint. As a precaution before installation, I compared the old one to the new one. The new one is missing three wires. One wire is brown with a connector that looks like it would attach to the coil type. The other two connect to the large red lead off of the alternator. One is about a 10-12 guage wire with a white braided cloth insulator. The other is a black wire with a white stripe that goes through a fusible link before it hooks to the red alternator wire. The questions:
1. What are these wires for? (I have wiring diagrams for '70 and '71, but cannot figure this out.)
2. Should I take the wires out of the old bulkhead and put them into the new one? If so, how do you get the spades out of the old bulkhead?
3. Should I send the new harness back to the supplier (who has to send it back to the manufacturer) and wait 10-12 weeks to get it back?

I'm trying to get this thing ready for Chevelle-abration. Since I'm not thinking clearly at the moment, I would appreciate any and all feedback.

 

[chev64]

Alan,Leo here, Does your dash have a tach? If it does the brown wire thats missing that appears to have a coil type connector may have been the tach wire. The other ones that go to a fusible link will power something. They can be removed from the bulkhead connector and be installed in the new harness, but I'll have to check on the method. My brother-in-law did it to his 71 to install a tach wire and an HEI connector.

 

[Fred Aldrich]

I agree with Leo
Tan - Tach lead
Black w white stripe and fusible link - GM style ammeter lead
White cloth covered - Not so sure on this one but only white cloth covered wire I've seen in my Chevelle ('69) is the resistance wire that powers the coil.
Circuit diagram from '72 Chevrolet Service Manual wasn't much help.

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Fred Aldrich
Web Site: www.GeoCities.com/~69_chevelle




[This message has been edited by Fred Aldrich (edited 03-28-99).]

 

[67ss396]

Are you talking about the engine wiring harness or the forward lamp harness? The engine wiring harness does not go to the alternator. It goes to coil, wiper motor, starter solenoid, temp & oil press senders, heater blower, etc. The forward lamp harness goes to alternator, horn relay, fwd lights, etc.etc. The black/white stripe wire with fusible link is for ammeter gauge and would be in forward lamp harness. If the white braided covered wire has a purple/orange thread in it it is a resistor wire that goes to + side of coil, and it is in the engine wiring harness. Hope this helps.

 

[Wes V]

If it's not what the seller said it should be, then send it back.

What may save time is to ask Year One who the manufacturer is and then contact them directly.

I'd bet that it's manufactured by M&H Electrical and that they will correct the problem.

Wes.

 

[Havoc]

ummm, for some strange reason, i'm pretty sure the 72's had the alternator wires incorporated into the engine harness, cause the 72's had internally regulated alternators. yeah, the brown wire leading to the coil is probably for the tach, but i know in 71-72 they came through a plug on the firewall. i also agree that the wire with the cloth braid is probably an ignition resistor wire. dunno about the ammeter wire though. i spent the whole day rewiring my 70. didn't burn anything up!

------------------
Ian McDermott
1970 Chevelle SS 396
Columbia University
New York, NY.
E-mail: [email protected]
Web page: chevelle.dhs.org
ICQ UIN: 3923441

 

[Alan F]

Update:
I talked to the manufacturer of the wiring harness today. They asked me to send my old harness (what's left of it) with the new one back to them. They will modify the new one and turn it around in a few days.

The engine harness does have the provision for the alternator on it. If my helper had shown up yesterday, I was going to attempt to trace the wires on the dash side of the bulkhead to figure out where they went. Based on some of your responses, I thought that they may have used a generic wiring harness since the car has neither a factory tachometer nor ammeter. The white braided cloth shielding on the large wire is the same that you would find on the positive coil wire, it's just a much larger wire. As soon as I find out what the wires are for, I will add that to this post as well.

For now, my problem is solved, albeit not timely. Thanks to all.

 

[Alan F]

Last update:
The manufacturer of the harness called me after they received it. They suggested the harness that I sent to them was a " service replacement" unit. They stated that the unique original harnesses were only available for a short time after the cars were produced. Then, they would produce a more generic wiring harness. They also confirmed that the brown wire was for a factory tach (which the car doesn't have), the black wire with white stripe was for an ammeter (which the car doesn't have). They had no idea what the large white-cloth shielded wire was for. So they did nothing to it and sent it back.

After speaking to them on the phone, I pulled the bulkhead attached to the fuse box apart. I was able to confirm that there were no wires in the bulkhead to accept the suspect wires in question. I wish I had done this first (Which is why I am posting this update - for your benefit!). Thanks to all for your inputs.