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Discussion Starter #1
So I'm rewiring the car (-66 Coupe, 302/C4). The old looms were completely destroyed by time and the work of previous owners. I really dislike electrical work, in part because I suck tremendously at doing it, and find it frustrating like nothing else. Not sure which is cause and which is effect, but that's beside the point.

I have the under-the-hood wiring all set, I believe. Everything lined up with the wiring diagrams I have, so I feel pretty good about it. Under the dash it's a little more challenging. In a what-could-go-wrong moment, I decided to see if the car would crank as it is. It did crank, and as a matter of fact wouldn't stop until I disconnected the battery. My assumption is that this indicates a short, but I'm not sure what I'm basing this on. After disconnecting and reconnecting the battery, the car doesn't start trying to crank until I turn the key again, but I can tell that it's drawing from the battery as soon as the shoe goes on. However, if I disconnect the alternator harness, it stops. Is this because I'm breaking the black magic voodoo chains of electricity in the car, or does this actually indicate that the alternator is crap?

Thanks,

TGV
 

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So what replacement harness are you using? Probably the first thing that needs changing is your attitude on electrical work.:shrug:
 

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Discussion Starter #3
Under dash and main under hood are Midlife rebuilds, alternator harness is Scott Drake. Also replaced battery cables, and ground wires, and the starter is new.

My attitude to electrical work is perhaps better at most times, right now I'm just frustrated with having done something wrong after having put a lot of work into it.
 

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Under dash and main under hood are Midlife rebuilds, alternator harness is Scott Drake. Also replaced battery cables, and ground wires, and the starter is new.

My attitude to electrical work is perhaps better at most times, right now I'm just frustrated with having done something wrong after having put a lot of work into it.
I get it! Some people are predisposed to hating electrical work just because. Did you replace the ignition switch. I did with an offshore one from this sites most favored vendor and it failed within minutes. Reinstalled the original that is mostly functional and looking for an NOS.
 

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I decided to see if the car would crank as it is. It did crank, and as a matter of fact wouldn't stop until I disconnected the battery.

It sounds to me like your starter solenoid got stuck in the closed position. Cranking an engine with a weak battery can cause the contacts inside the solenoid to "weld" themselves together. Cheap Chinese Crap solenoids can do that even with a strong battery.
 

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It sounds to me like your starter solenoid got stuck in the closed position. Cranking an engine with a weak battery can cause the contacts inside the solenoid to "weld" themselves together. Cheap Chinese Crap solenoids can do that even with a strong battery.
Very common on GM starters when low voltage is applied. Yours may just be "sticky" since it didn't re-engage when you hooked the battery back up. The solenoid is the only connection from the battery to the starter. Make sure your "s" and "i" terminals are wired properly on the solenoid, and the "s" isn't hot when you let off the key. You can disconnect the wire from the solenoid to the starter and test if it's wiring or component.
 

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My thoughts are either a bad solenoid or somehow the "run" position on the ignition switch is connected to the "s" terminal on the solenoid. That would keep the solenoid connected. Or maybe the run is feeding the s wire somewhere
 

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Discussion Starter #9
Thanks, guys. Several things to dig into, and generally feeling more positive about it now. Up and at them!

Thanks,

TGV
 

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Thanks, guys. Several things to dig into, and generally feeling more positive about it now. Up and at them!

Thanks,

TGV

Hang in there! I completely replaced the wiring in my 66 project with a Painless harness. I'm pretty good with electric but found myself frustrated many times. Sometimes I would have to step away and relax, taking a fresh look often made the problem appear obvious. Mark things once you know what they are and keep track of your changes so you don't compound your problem.


I'm guessing solenoid too. Most are complete garbage and even the good ones fail sometimes.


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Discussion Starter #11
So far, I have found and corrected two things; battery and alternator. Humorously, those are the two items I took to the local parts store and had tested. As I mentioned, I'm no good at troubleshooting electrics, but it seemed to me that there was a short in the alternator. The parts store claimed it was just a hair low on the voltage, but nothing else wrong. Put a new alternator in, short is gone, but car still won't crank.

Parts store claimed battery was great. I guess it was producing the volts but not the amps? New battery, and the car cranks great. Now to figure out what's going on with the dashboard lights.

Thanks,

TGV
 

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Well, looking at the photos you posted, if you have a '66, which means you have an ammeter and not a warning lamp, the STA (stator) post on the alternator is not used, unless that wire you have connected at 12 o'clock is going to a choke heater.....
 
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