Help with electrical issues

[Gary C.]

Hi to all and Merry Christmas. I would welcome any suggestions for sorting out my electrical system problem.

I have a 67 400HP A/C coupe. I had what I thought was a shorted alternator terminal that resulted in a burned wire. The wire was replaced back to the connection in the harness and my alternator was rebuilt. I just got it all back together and it looks as though I have more issues than I thought.

I have 13.4V across the battery and at the large terminal on the starter sylenoid. I have no voltage any where else on/in the car. Can someone walk me through the steps to determine where my problem lies. I prefer not to just replace electrical parts/harness until I get lucky.

Thanks in advance.

Gary

[Bill M.]

Re: Help with electrical issues

Gary

I would unwrap the entire harness and check it wire by wire. I was having problems with my 67 350 ac coupe and did the same . i retaped harness and instaled only to have it melt down a few weeks later. Thank god for Halon fire extinguisher.
Merry Christmas

[Larry M.]

Re: Help with electrical issues

Gary:

First, Merry Christmas to you and the family.

Second: I think you have a burned wire or fusible link. Possibly the one (brown wire - fusible link) at the starter terminal connection. It feeds the main 10 gage red wire and just about everything else in the car.

For the AC cars, the horn relay is a critical junction point. I would start there.

You should have the 1967 Service Manual. The electrical wiring diagrams are in the back pages.

I would check voltage at the horn relay terminals where all the red wires connect, at the alternator main terminal, at the AC in-line fuse holder, and at the orange fusible link at the voltage regulator terminal(s). If no voltage anywhere, then the brown fusible link at the starter connection is probably toast. If voltage at some points, use the electrical diagrams to begin tracing it down....and let us know what you find.

You could also have a problem at the firewall connector(s). We'll look at that next.

Larry

EDIT: Gary, If you want, call me today. I will be working around the garage. I have both GM and DR REBUILD color coded electrical drawings for 1967. I also have a factory AC car. I can walk you through them.

[Steven G.]

Re: Help with electrical issues

Gary, from pos. battery, trace smaller wire (red) that travels to alternator and also goes to #3 terminal on voltage regulator. If you do not have battery voltage at these termnals, there is an open circuit probably due to bad wire or 1 of 2 bad fuseable links that connect at junction block. (ign. switch off) This is the beginning of the current that will feed main wiring and fuse block under dash. A wiring diagram sure does help after this point.

[Gary C.]

Re: Help with electrical issues

thanks to all

I have voltage at the large starter solenoid terminal but I cannot get voltage at the other terminals on the solenoid. Does that mean somthing is open in the solenoid itself?

[Larry M.]

Re: Help with electrical issues

Gary:

No. They get their voltage from other places: ie. the ignition switch. The ignition switch gets its juice from the firewall connector(s). The firewall connector(s) get it from the horn relay terminal block, which gets voltage from the starter solenoid main (bat) terminal, which gets it from the main positive (black) battery cable.

Larry

[Joseph S.]

Re: Help with electrical issues

Gary, There should be another wire with a 3/8 diameter terminal attached to the large lug of the starter along wih your pos battery terminal. This wire feeds directly to your horn relay. If you do not have power at your horn relay then you have a burned out fuseable link at the starter area. You can buy this wire by the foot at any auto suply store. Repair this bad link and you should be fine if your alt issue is corrected.

Merry Christmas, Joe

[Gary C.]

Re: Help with electrical issues

many thanks to all, I indeed have a burned fusible link at the starter.

Got to love this board.

[Jimmy G.]

Re: Help with electrical issues

Gary

I think I know this car very well. If you are still planning to drive it a lot, I would recommend a complete wiring tranfusion. I have found that 40+ year old wires get brittle and contacts get corroded, especially on an a/c car. Small price to pay versus a catastropic electrical fire.

[Wayne W.]

Re: Help with electrical issues

Gary

I think I know this car very well. If you are still planning to drive it a lot, I would recommend a complete wiring tranfusion. I have found that 40+ year old wires get brittle and contacts get corroded, especially on an a/c car. Small price to pay versus a catastropic electrical fire.

Let me guess. White with blue?

[Gary C.]

Re: Help with electrical issues

yes, White and blue. And yes again jimmy, just as you suggest the wiring is brittle. The wires at the starter end have evidence of prior repairs. I was able to make the repair and now I know the car runs again as it should. I will take your advice and replace at least the ignition harness some time this winter.