hkestes

Well I have been having electrical issues with my 37 Plymouth with 96 model 360 since May.

Had starting issues early on replaced the battery, starter, battery cables and added grounds a second new starter. Unfortunately, due to my own negligence I didn't get one of the wires to the starter back into the loom clip and it got loose and wrapped around the end of the steering column causing a short and all the wires under the hood to burn up. Luckily I always have a fire extinguisher in the car so it was confined to the wiring.

Anyway, I rewired the entire car with a new EZ harness and things were looking good once more. Then the electron demons reappeared. Driving down the road on my way home and noticed voltmeter not registering any charge. Made it to the driveway and checked belt good and tight, all wires with good connection etc. Next morning started it with a jump and voltmeter reading 12 volts. So off I go only to look down a few miles later to no reading on the voltmeter.

Pulled the alternator and had it checked everything shows good. So I swapped out the voltage regulator. Things seemed to be good after I jumped it again and made it home.

Started the car yesterday again with a jump and started the stopwatch on my phone. A couple minutes after I started it the needle on the voltmeter slowly started falling from about 12 volts and at three minutes and 14 second after starting it hit zero.

At this point I am clueless as to where to turn next. I am not the brightest bulb in the pack when it comes to electrical and was actually surprised when everything but the brake lights worked after the rewire.

Is there an internal voltage regulator in a Denso alternator or something else internally that could be heating up and shutting it down? Any suggestions would be appreciated I'm at a loss.

fivepoint

Do you have power at the battery post on the alternator at all times? I think your voltmeter should read at least 13.5 volts when the engine is running. As always, make sure every component has a good ground.

RacerHog

That story is funny to some extent. Thanks For sharing...lol
Just got love them Grimins...
Yes: to the question, Most of the Denso's have internal regulators.
Question: Are you using the 3 wire Denso Alternator? Telling us how you wired it might help.

Sure glad you didnt loose the whole car with a fire... That would have been a dam shame !!!!

Iowan

Automotive wiring is something you either get or don't, I have to approach it like you did and start over. I've got my Ford project that's going from a genarator to alternator and my solution is to rewire the entire car.
good luck

xaza

Have you tried charging the battery with a charger. Get it to full charge and see if it takes longer for voltage to drop. Shut off engine and check for any amp draw off the battery to find parasitic draw, need to do this while there is some juice left so don't wait for it to drop to nothing. Check with a meter your voltage at battery like fivepoint said, both running and not.

hkestes

Guys been swamped, but wanted to get back to this. I installed a new alternator and still pretty much the same. Will start immediately with a jump, volt meter shows in the 12 to 14 volt range for a few minutes then slowly drops to zero. Unfortunately I don't have a battery charger will have to look at getting one. Here is what I have.

Off back of Alternator:
Red wire is Alternator Power, Black on same post is the Alternator Bypass wire to the starter (which post on the starter should this go to? I have it on the same post as the positive battery cable.)
White wire is the alternator excite. The blue wire coming off the voltage regulator branches off the alternator excite.
Light Green wire goes to the Voltage regulator.

RacerHog

Dont need the Black Wire
Dont need the Blue off the White.

Red From Alt. Should go to Battery + >>>>>> Should be like 10 Gage ?
White wire should have 12 volts when key is in the run position.......
Light Green, Unplug the regulator and put a jumper wire in it. Check to see if that fixes the issue?

fivepoint

I agree with Bob. Tape off the black wire. The red wire should be 10 guage. The red wire can connect to the battery post on the starter.