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Alternator suggestions...

Oystercopy

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Hey guys... I've been having issues with the Challenger not keeping bright lights in the interior when I have the headlights on at night. I notice that even though I have the car warmed up, she'll die instantly when I turn the headlights on? I realize this is a power draw of some kind, but here's what I know so far:

Finally grounded the voltage regulator, which had come loose from the firewall, due to the screws being stripped. Before I knew that it had come loose, I had gone through one alternator. Live and learn.

The alternator I purchased, was at an Auto Zone and was probably a very cheap imitation of a good alternator ($60? or so?), so I'm wondering if this is (at least) contributing to the issues.

I'm wondering about putting a higher amp alternator in its place, possibly one of the Powermaster series from Summit or someone like that. Thinking about going to a 95-Amp, but a little worried about overloading the system and melting wires. When the car was restored years ago, they remade much of the engine wiring harness, because it does not look factory and looks like more of a "homegrown" effort. I believe they did a really good job, and I have had no other issues with the wiring and I've owned the car for over 2 years now. Everything else seems to work fine.

I am of the belief that the cheap alternators simply don't put out enough juice, especially at idle, so hoping someone has installed one of the higher amp units with good success.

Thanks in advance!
 

Chryco Psycho

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Well if you think the Auto Zone rebuild is a cheap product Powermaster is true china Junk , I have seen new ones last less than 1 week !
The stock alt doesn't turn fast enough at idle when it is heavily loaded , lights heater wipers etc , I have had local rebuilder upgrade the stock alternators or you can adapt a Denso unit , Mancini has a kit for the Denso type .
If you go to a higher output alternator you must install a bypass from the alt output to the bat terminal on the starter relay , the ammeter can only handle 60 amps max & it doesn't hurt to bypass the ammeter also by connecting both wires to 1 terminal .
 

ted s

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have had a pwoermastrer on my challenger for 20k miles, no issues
 

Chryco Psycho

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Cool some of there products have to work or they would be out of business but I have had at least 2 bad experiences with Powermaster parts
 

70chall440

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A few notes;

First off put your headlights on relays and it will take the load off the switch and make your headlights a fair bit better

The Denso units are good and I run them on all my cars, however as Chryo said you need to install a bypass

Check ALL of your electrical connections, clean them and ensure they are making good contact. This is probably one of the biggest issues with old cars which develop problems and then people just throw parts at them attempting to fix an issue

Install more grounds, cannot have too many especially with Mopars. Ground the engine to the K frame, engine to the firewall, dash to the firewall, engine to the radiator core support, etc.

I firmly believe that Chrysler hired the bottom 10% of the electrical engineering graduating class for many years... JK JK...
 

Challenger RTA

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You said, "she'll die instantly when I turn the headlights on?" As you know that's not normal. First think I would have the battey checked. motor not runing battery full charge would be around 14v. motror runing 14.8v.motor will start and run with less then 12v. Add an ACC dead stop is what happens. taking into concederation all connections are good. then I would do As 70chall440 said "clean all termanals. battery.firewal connectors and grounds." And where the alt mounts. I would do this before condeming the alt again.​

Check to see what the votage is runing and not running. just and other thought foot switch bad? An alt will charge at a high idle. also a different size pulley will effect the charging at different speeds.
 
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ctaarman

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Adding to the other comments, if your car still has the firewall bulkhead connector, unplug it and clean all the oxide off the connector pins and make them shiny. 500 grit works well. Then coat each with a thin coat of electrically conductive grease before reassembly. This will protect and insure a better connection.

This connector was only designed for 60 amps at best so never use the original bulkhead connector with a high output alternator. Many a Mopar engine compartment fire and total vehicle loss are attributed to this.

I was lucky on my AAR. I had already pulled the HO alternator the previous owner had installed. One day while on a leisurely drive, the car just died. Nothing worked, yet when I flatbeded it home I could read voltages on a meter.

I read about the bulkhead connector issue and pulled mine. The two highest current connectors were both heavily carbonized and one had heated sufficiently to slightly begin to melt the plastic. I did the above procedure and haven't had the issue again.

The Mopar ammeter circuit design carried over all the way from the 1930's. However I am convinced that Chrysler must have hired an engineer from Lucas to rationize keeping it in place for over 30 years😜.
 

70chall440

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Great video in terms of tech, hard for me to look at that mess of chopped up wires, crimped connectors and liberal application of electrical tape... LOL If that were mine I would spend some time cleaning up that mess, oh and the crappy kinked fuel line as well... LOL
 

Ctriton20

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Check to make sure your voltage regulator is putting out 14 volts. I purchased a few stock ones that didn't. So I installed an adjustable voltage regulator and was able to set it to the correct voltage.
 
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