Alternator problems again

Hello I thought I would re-post my question after getting back to work on the Cj6 build. To re-cap the problem, I have done a frame off build so everything is new. I started off by putting in a "Painless Wire Harness" and I swapped out my old Distributor and Installed a HEI distributor.

When I first hooked everything up. The new Alternator got extremely hot and I believe I fried it. I had it checked out and it was toast. I had run it for 5 minutes. I had hooked it according to the Painless instructions. So now I’m on my second Alternator and it seemed to last a little longer than the first. But when I remove the “positive lead” off the battery, the engine dies. And this alternator is getting hot as well.

And I have never seen any indication of voltage or amperage on my gauges. The radio isn’t even working! I had to ask for advice from you guys. I am dreading the call in the morning back to Painless for advice. So far they haven’t helped much. After I finish with them I’ll go get the alternator checked out. Just to make sure it’s OK. I am open for any advice.

Thanks in advance,
Ken

 

What alt are you using? Do you have a wiring diagram for it? Have you checked the voltage at the alternator with a voltmeter?

Is the alt internally regulated or external?

When I swapped my 4.0 into my 5 I went through 3 parts store alts till I had a good one. Most of them only lasted a few days. Funny, after the 2nd time I came back they were convinced it was the vehicle wiring, except when they test the alt it was definately bad!

Kevo

 

it almost sounds like your alt is grounding out. Not completely sure but thats what its sounding like..some where down the line. As with ghetto fab, i went through 2 kragen alts before adapting a chevy alt to the jeep. Good luck in your quest.

 

I'd ditch the painless part of the alt wiring and wire it correctly for the alt you have. Your alt should have a wire to a good ground, and the output should go to the batt side of the stater solenoid. Other than that you need a sensing wire and a field exciter.. If you are still trying to use the original Motorola alt you need to upgrade..

 

Bad things happen when you test your alternator output by removing the battery cable while the engine is running. That test was fine for generators but alternators can produce voltages beyond 120 volts. Yes you may get by with it a time or two but it will eventually get you and it will burn out anything that is turned on. In this case I think your OK because I think like Howard that the alt output has been wired to ground somehow. With everything hooked up except the battery wire that goes to the BAT terminal on the alternator, you should have battery voltage on this wire at all times.

 

Just a small update. The newest Alternator checked good. So I called Painless to ask if anything I've done different than just hook it up. When I informed him that the Electric Choke remains hot (12 Volts) even with the Ign. Key in the off position. He ask me how old my harness was. I told him I had purchased it around Christmas from Quadratec. He then openly told me there was a Mis-wireing done at the factory. He has since sent me a new wire diagram to follow and re-pin some of wires that run thru the firewall fuse box. The part number of my Harness is #10110. So if anybody has one of these you might want to check with Painless before installing like I did. I really lost some sleep on this one, It's not good to see newly installed parts go up in smoke.


I know I'm not out of the water yet. But it sure was nice to know what has happened so far wasn't my fault. Now it's off to the garage to fix the wires and reinstall the alternator for the 3rd time. I'll repost the final outcome when I get positive results.


Ken

 

So, just to make sure things are ok before you fire it up, do you have a wiring diagram for this alternator other than the one painless has given you? It would be a good double check of things to make sure they are wired correctly.

Kevo