Ever since I got her, my 74 has had an electrical leak somewhere in the system that drains my battery if I leave it connected over night. So while I've been working on it I just make sure that I disconnect it before I head in for the night. Yesterday as my dad and I were working on the timing the battery needed a charge. So I tried to hook up a jump pack and as soon as the second cable would go near the post it would spark. Even with the ignition off and key out. It seems as if I need to replace my harness now. What kits have you guys used in the past? Also, would it be worth it to send it off to someone to replace because I hate working with electrical systems? If it's not that difficult I could probably manage, but it would be really annoying. Thanks.
A nearly dead battery will spark when a jump box or charger is connected, the better jump boxes have a switch that should remain off till cables are connected... The spark is also no doubt partly because of the unknown current draw, find that and likely your problems will be solved... It's possible but I doubt the wiring is even the problem, more often than not leaky rectifiers inside the alternator are the issue... Disconnect the alt wiring, charge battery and see if that is your issue...
No need to throw out the baby with the bath water....so to speak. Find out what your real problem is. I bet it is a simple fix compared to replacing the entire wiring harness.
Thanks for all the responses! I had the alternator checked a few months ago (it's been sitting since) and it tested fine. I also replaced the voltage regulator. I have an ignition switch at I haven't put in yet, could replacing that solve the issue?
Does your car have an aftermarket radio. It has been my experience that 90% of electrical draws are caused by an aftermarket radio or amp. Though you should still do a draw test with a multi meter.
No radio period at this point. But there are connections for it. What is needed for testing the components? Just a voltmeter?
A test light is usually better, unless you are versed in their usage, a high impedance DVM will often lead you astray... Disconnect the leads to the battery side of solenoid, then connect light between battery cable and the removed lead(s) one at a time to see if either lights the lamp...(should be two, one for alt and a second that powers the other wiring)... If you get a light that circuit has a problem...
When I had that problem I pulled a battery cable and put an ammeter between the battery and the cable. Found it was drawing a little over one amp all the time. Just pulled fuses until the current draw went away and I isolated the circuit with the problem.
Start with those circuits that don't need the ignition on. Lights and horn are on the circuit breaker in the light switch so you have to unplug it. dome light is on a fuse. I still would pull the wires off the alternator and see if draw disappears, the diode trio not the main rectifier can have a small drain like you describe. When I was a mechanic during college I would have to replace an alternator for a $4.00 part.
