Went on a trip and noticed a voltage drop. On the way home towing voltage dropped to below 9 volts, Stopped in a small town and bought a couple batteries due to mine being over 8 years old. Made it home but my alternator is not charging. Now how do I test to ensure it’s the alternator and not regulator? And where is the regulator on this beast?
Thanks.

 

Aren't most regulators built into the alternator these days? It's probably the alternator. Take it out and have it checked for free at Autozone. Might as well replace it while you're at it. It's only about a hundred bucks that will have to spent on it sometime down the road anyway.

 

Regulator is part of the Powertrain Control Module (PCM).
The most common failure on the alternator is brushes and commutator ring. I replaced my brush pack for $5 and turned the commutator smooth with a file.

 

Thank you for the info do you know how to test both components to determine the culpret? and where is the PCM located?

 

I purchased a high output alternator on E-bay for around $200 - new with a lifetime warranty.

 

I recently (April) changed both my batteries and after the change the charge rate was low. I thought it may be the alternator and was ready to remove it. I thought I would give it a chance, sure enough the charge rate did come back to normal after a few days and hasn't acted up since. Don't rush in.

 

thanks to all for the input

 

if your crank sensor is bad your alt. will not charge i would start there......

 

PCM is located on firewall in engine compartment. Test the alternator first as PCMs rarely go bad. Many auto part stores have a test bench and do it for free. Bad brushes or rectifier bridge show up on a good bench test.

 

Thanks again