Author Topic: Ground for alternator?  (Read 2046 times)

Offline shadango

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Ground for alternator?
« on: May 02, 2015 - 12:02:23 PM »
Some of you know I had alternator issues on my trip up to Carlisle last year.....after searching the grounds all day I ended up buying a new Powermaster alternator to replace the duralast I had.  Well, I had forgotten I had the old alternator and I was actually able to return it for CASH after 5 years of use!!!! Go figure!    The old one was in the powermaster box in storage.

And that (finally) gets me to my question.....

On the powermaster box it says "Ground alternator to b lock with 10 awg min wire. many brackets have a coating or plating that keeps the anternator from charging properly".................does anyone here do this on theirs??  I have never noticed anyone in a mopar at cruises etc doing this....

It also advises to "change the alternator charge wire to a heavier guage wire if new alternator is higher amperage than original".  This new alterbnator is labeled as 90amp......think I need to worry about the stock wire?  Its a newish one, bought from a place 5 years ago that does OEM style harnesses.

Thanks all!!




Offline TelisSE440

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Re: Ground for alternator?
« Reply #1 on: May 02, 2015 - 04:56:19 PM »
If you are using the same brackets as the old Powermaster alternator (and that alternator's problems weren't due to ground issues), you shouldn't have any problems about grounding. But you have to upgrade your gauge wire and connect it directly to the starter relay where the battery cable also connects. The factory setup as Strawdawg correctly said in a topic I posted earlier, was marginal when new and with years passed, it became worse. So if you leave the factory wire then and don't do the bypass, you're in danger of melting your wires or worse catch a fire. When you do the bypass, you won't have any problem except for your ammeter which won't have accurate reading from now on and it would be better if you added a voltmeter.

That was the post http://www.cuda-challenger.com/cc/index.php?topic=105982.0

Offline Strawdawg

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Re: Ground for alternator?
« Reply #2 on: May 02, 2015 - 07:25:15 PM »
normally, it should be fine.  I usually take my meter and measure the voltage drop between the alternator case and the negative terminal on the battery as a double check.  If it is above 0.1v, I check the mounting surfaces to see if there is a connection problem with them.  I ran into this once with a powder coated alternator case..but this was an exception

Offline 734406pk

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Re: Ground for alternator?
« Reply #3 on: May 02, 2015 - 08:03:21 PM »
If you are using the same brackets as the old Powermaster alternator (and that alternator's problems weren't due to ground issues), you shouldn't have any problems about grounding. But you have to upgrade your gauge wire and connect it directly to the starter relay where the battery cable also connects. The factory setup as Strawdawg correctly said in a topic I posted earlier, was marginal when new and with years passed, it became worse. So if you leave the factory wire then and don't do the bypass, you're in danger of melting your wires or worse catch a fire. When you do the bypass, you won't have any problem except for your ammeter which won't have accurate reading from now on and it would be better if you added a voltmeter.

That was the post http://www.cuda-challenger.com/cc/index.php?topic=105982.0


The ammeter bypass is a great improvement to the electrical system, just make sure that you don't also connect the factory original black alternator output wire to the alternator together with the bypass. Doing so will "jump" the factory "fuse link" protection to the dash harness. Check the wiring diagram to confirm this.
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