I know this question might be hard to answer but lets try anyways.... I'm dealing with a short somewhere in my '71 Comet. So far, battery dies after about an hour and won't start up. I've double checked if the battery is holding charge and it's good. Brand new alternator, so thats good too. With the battery fully charged and vehicle off I put a test light between the positive terminal and the red leed and the light goes on. So something is drawing power with the car off. Then I pulled each fuse out one at a time to see if the light goes out and find no change... I removed the stereo so thats not pulling power either. Is there anything else that could be pulling power while the cars not running that isn't connected to the fuse panel?
There should be three connections between battery and input to solenoid, one being the battery cable, one power to fuse panel and one from alternator... To troubleshoot, remove battery cable and leads from solenoid, place your test light between batt cable and each lead, one that lights has the problem... Also check between battery cable and solenoid, if it has a internal issue may be powering ignition through the green/red wire(though should not be able to shut off engine if this were the case)... If problem is in the lead to fuse panel you'll have to start unplugging ign switch, headlight switch, brake switch, signal switch etc... Could be a sticking voltage regulator, and never believe a alt isn't the problem till you've performed above test...
If you have an ammeter instead of just a light you can see how much current is being drawn. Sometimes provides a clue.
So I have a pull of 83 milliamps.... Tom, i found the draw from the battery to the yellow wire connected to the solenoid, I'm assuming this is going to the fuse panel. Now, start pulling fuses out again i suppose.
If pulling fuses doesn't show anything that wire also goes to the light switch and the horn. They are protected by circuit breakers in the light switch.
Ahh you're on the trail now, 83ma will cause issues... Yes yellow is the feed for everything in the car... Do you have a aftermarket stereo with preset memory?? These have been known to cause issues...
Pull the cluster, loosen the heater controls and you'll be able to depress the button that that lets the shaft pull out...Next unscrew the dash retainer nut and switch will drop back... Once you get access to connecter unplug it and check current draw again... If it's still there, the switch isn't the problem...
Wooohooo! Just wanted to thank you all for the help on this one! Turned out to be the 42 year old light switch. Tom, kudos to you! FYI if this happens to you the light switch fault pulled 0.82 amps or so from the battery when the car was off
Glad you found problem that was getting serious, a .82 amp draw will be creating heat, could start a fire... No doubt started as a much smaller draw with burned/carbonized grease between contacts the likely cause... Would be similar to issue with 'late '80s & early '90s Fords that had spontaneous ignition switch fires... After this I'm checking current draw on mine though I suspect it's OK, the almost 10 year old battery cranked it just fine after setting for over two weeks...
