I went to start my 69 yesterday and it just cranked. I also smelled a feint burning odor. Turns out the wire to the alternator melted. Any ideas where to look for a short. There is noting obvious. The only recent change was a switch to LED headlights. The wiring for the headlights looks fine. A photo is below.
Steve
Steve, I’m not too sure, but Im thinking the Alt might have an issue (diode?)
Correct. Time to get the alternator tested. It’s probably bad.
Thanks for the replies. My alternator was probably last replaced about 20 years ago.
Steve
I pulled the alternator tonight. It looks like I also fried the plug where the alternator harness attaches, and less than an inch past the plug. I can’t identify the name of the harness with that plug. Does anyone know the name so that I can identify and order one. If anyone has just the plug or the plug with partial wire I may be able to get that to work. Thanks.
Steve
Steve
Unfortunately the harness that the alternator plugs into is not reproduced. Midlife repairs them.
The alternator harness is available so long as you remember Cougars and Mustangs are not alike.
Luckily, you can get a reproduction harness that goes from the dog bone on back of alternator to that plug. WCCC has them in stock. Looks like that one is the more severely melted one.
That has already been ordered. The problem is that the plug it goes into is also damaged.
Isn’t this the repro of the harness that the alternator plugs into? https://www.ebay.com/itm/275635904071?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=kJb3KmqFRfi&sssrc=4429486&ssuid=AG72V1H_Qcu&var=&widget_ver=artemis&media=COPY
Looks like it is. If Vic made it I would lean that way but the repair done by Midlife will be a lot cheaper.
I typically don’t repair alternator harnesses, since most are reproduced and are engine size dependent (I can’t tell what engine donated cores are from). Thus, I typically don’t have the alternator-side plugs because of that. I can repair the engine-bay side of most harnesses, though.
I was hoping to find the plug that the alternator harness plugs into and then splice that in rather than pulling the entire harness which looks fine from about an inch beyond the plug. Has anyone tried to use the plug on a headlight extension wire harness? It looks like it may work.
Steve
No but I bought a plug and wire from WCCC to repair a customer’s harness. I soldered the wires and used shrink tubing. You can’t tell the repair happened.
I am hoping to find a plug that works and then solder the wires into the harness under shrink tubing. I’m waiting to hear from Don Rush. Not much left to check in the junkyards near me.
Seem to have fixed what burnt out the alternator harness. New problem that developed at the same time is that the radio does not turn on. I know I need to replace my ignition switch at some point since the accessory position does not provide power. This started last year. Any chance this is connected?
Steve
Unlikely. Radio gets its power from the fuse box, shared with washer pump for windshield and backup lights. If these don’t work, then the problem is probably in the fuse box: a blown fuse, perhaps.
Thanks. I will check next weekend.
