melting power wire.

[Joseph R.]

have finished 66 coupe, 427, air power widows power brakes and power steering
put battery in for first time and when we hooked up we had smoke and heat off of the red power wire from just before voltage regulator towards front of car. unhooked two firewall plug ins to fuse box and retried, more smoke ,wires are intact but sheathing melted. I am not electrically astute. Any suggestions. don't want to burn down down the car and or house

[Don H.]

Re: melting power wire.

Joe
black wire goes on Hot, and brown (some say red wire) goes on Ground. Sounds like you crossed them.

[Joseph R.]

Re: melting power wire.

I thought that but I double checked here are some pictures. I wonder if it is at the starter because the air con harness and the regular harness has hookups to starter also the voltage regulator was an eBay to get the correct date code and the horn relay was original to the cart. maybe I didn't hook them up correctly or the regulator was a dud or the horn relay burned out or incorrectly connected very hard to tell by wiring diagrams

[Leif A.]

Re: melting power wire.

As Don stated, check your battery cables to be sure you're putting the correct cables on the correct terminals. That engine harness is "toast"...literally. I wouldn't attempt to utilize that harness going forward. You can't determine (visually) what has burned up inside that harness...spend a couple hundred dollars and get a new harness being very careful to not ground/short any of the terminals on the harness when hooking up. You state that you're not "astute" when it comes to wiring. These cars can go up in flames very quickly...please seek professional help with this issue.

[Rick N.]

Re: melting power wire.

The black wire you have hooked to the starter post is a ground wire.

[Richard M.]

Re: melting power wire.

The black wire you have hooked to the starter post is a ground wire.

Agreed... That Black wire(the one with the exposed bare terminal) on the BAT+ terminal is a Ground wire for the Heater Blower and Wiper Motor Ground. I'm not sure that misconnect would cause such a catastrophic short as the result.

What wiring diagram did you use when you reconnected wires to the Horn Relay? If you used the Service Manual Wiring Diagram, that could have caused you to create a miswire as the wiring diagram is wrong.

There are 5 wires to the Horn Relay. A small gauge Black and Green go the the blade terminals from the horn button/horns. There are 3 other wires, a Red, a Black, and a Black/White tracer. These are the Power and Battery Gauge wires, and Ground feed.

Red goes to Buss Bar. (Main Power Feed from BAT+ Solenoid terminal)
Black/White goes to Buss Bar. (Source to Battery Gauge Sense terminal)
Black is Ground which attaches to Horn Relay Mount Bolt which screws into Radiator Support.

The 1966 CSM(and other years) Wiring Diagram is misleading and shows the Black(Ground) as being attached to the Buss Bar, not the Mount Bolt. This miswire would cause a dead short between Power and Ground and may be your fault.
This is a 1967 diagram error but the 1966 is also in error and excludes the Fusible Links.(1966 PDF attached and also shows error)


This shows the proper connections. Note the 12G Black is Ground attached to the mount bolt.

[Joseph R.]

[Joseph R.]

Re: melting power wire.

Also where do I mount that black wire that I currently have on the power bus?..

[Richard M.]

Re: melting power wire.

Also where do I mount that black wire that I currently have on the power bus?..

Joe, Please post a picture of the existing horn relay wiring to be sure. Also please post a picture of the LL diagram showing the Relay connections. You may have a old diagram which was a copy of the erroneous wiring.

I suspected that Black wire was on the Buss. If so that caused the dead short. The BLACK wire round terminal attaches to the Relay mount tab using the sheet metal bolt to mount the Relay. The Black/White wire does go onto the Buss.

Here's the 1966 diagram showing the original and corrected views. Sorry thy're sloppy as I did them quickly but it should help.

WRONG


CORRECTED


Edit I found another diagram but not sure where it came from. It also shows the original error and correction.

[Richard M.]

Re: melting power wire.

Joe, One more thing. Your Engine Harness has been seriously compromised from the dead short. Internally, the Red and Black wiring has melted in areas you cannot see. These wire traverse all the way back to the Starter and beyond. Even if it isn't shorted after you correct the Black Ground miswire at the Relay, it is still very dangerous to use it.

You SHOULD replace the damaged harness.

It's unfortunate that you were bitten by the Wiring Diagram error. You are not alone.

Rich
PS Whenever I install a new harness in any Corvette, I temporarily add a 20A fuse to the main Red Wire at the BAT+ Solenoid terminal. This way if there is anything wrong with the Harness or the installer made a mistake(me!), the fuse will save the day. After testing I simply remove the fuse.

[John D.]

Re: melting power wire.

Dr. Joe, So sorry you had to suffer like this. You are now in for a major project and expense. Buy new harnesses as strongly suggested.
John Pirkle is no longer in business. (Right Gang???)
We have people in our chapter that could help you. Call me a 724-832-3786.
Good to see you at the last event. John D.

[Joseph R.]

Re: melting power wire.

Wow thanks so much will get back to you later today- working

[Dick W.]

Re: melting power wire.

Joe
black wire goes on Hot, and brown (some say red wire) goes on Ground. Sounds like you crossed them.

Bass ackwards Hooper. Black is B- and Red is B+

[Francis F.]

Re: melting power wire.

rich,
good stuff I will keep for my reference....thank s
Francic

[Joseph R.]

Re: melting power wire.

Thanks everyone for your help. Will do what you all said