Krisndan Posted February 22, 2014 Share Posted February 22, 2014 Hey all. Ok, so I'm about 3 years into a restoration of a 75 coupe. The one consistent I've run into is a buggy electrical system, but each issue has been resolved until very recently. I was in the process of putting all the pieces back together on the interior and putting back all the lights from a paint job - and I got the whole thing looking great - then I go to turn the key and fire it up a few weeks ago, there's a few clicks and there is NO power whatsoever to anything. Oddly, after sitting for a day or so, I came back to it and found that I again had power for a few seconds, then bam! I've tried disconnecting and reconnecting the neg. battery cable to try to re-set whatever is causing the problem, but time seems to be the only thing that works. I chalked it up to the crazy cold temps we've gotten here in northern Illinois. Yesterday, I go back and try again - I turned the key to "on" and all seemed fine. While checking the turn signals, I found I needed new bulbs. Today I put them in, tested it out, click-click, and again no power. !!! Here's what I've ruled out: 1) Two years ago, I swapped the fusible links for breakers - they have been great, and are still doing what they are supposed to. 2) I swapped out the interlock unit from a 76 parts car I'm working off of thinking that was the issue. Apparently not. 3) I pulled and hooked up a (used) voltage regulator from the 76 to see if that would do anything - no response at lockout. 4) Fuses are all ok 5) Ignition switch seems to be ruled out - lockout seems to happen only when something else tries to draw power, such as the radio, blinkers, or whatever else it's been to blasted cold to test. 6) Starter cables are in the right place, same with the battery cables. what the heck is going on here? Any suggestions? I have had this problem only since putting the lights and interior back together - it never did this when I had it pulled apart, in fact, I was able to drive it around just fine. As I write all this out, it seems like an obvious bad ground, but what's the deal with the lock? Can a fault in wiring for lights cause that? I need a fresh perspective here. Quote Link to comment Share on other sites More sharing options...
Krisndan Posted February 22, 2014 Author Share Posted February 22, 2014 Forgot to mention: Emergency switch was bypassed when I got it Quote Link to comment Share on other sites More sharing options...
NewZed Posted February 23, 2014 Share Posted February 23, 2014 Sounds like the typical dirty/corroded electrical connection, usually at the battery. Dirty contact > resistance > current flow > heat > expansion > loss of connection > cool-down > contraction > connection restored. Quote Link to comment Share on other sites More sharing options...
Krisndan Posted February 23, 2014 Author Share Posted February 23, 2014 That makes total sense. The battery cables don't look dirty or corroded, but I'll hit them and the starter cables with a wire brush. Maybe that's what's causing the interlock unit to go berserk. Thanks for the starting point - I'll post results as soon! Quote Link to comment Share on other sites More sharing options...
Krisndan Posted February 23, 2014 Author Share Posted February 23, 2014 Well, that seemed to do it! Armed with sandpaper and a small wire brush I hit just about anything that has contact with anything on the battery and starter, and a few ground points to boot. By the time I was done though, my toes were so cold that I tested little more than the blinkers. They didn't kill the power this time though, so I'm calling a win. Hopefully it holds true when it's not 20 degrees in the sun up here. Thanks for the input! Quote Link to comment Share on other sites More sharing options...
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