So the voltage regulator in my alternator is going bad hence the pulsing headlights that makes me feel heat score when driving at night.

The new 102 amp oem ebay alternator came with a 4 tooth pulley, so after installing everything I had to uninstall everything once again. Than after hours of trying to remove the pulley with a socket, I had to buy an impact to switch pulleys around. This made the switch easy as butter.

After installing everything again, I was not so happy to start the car and notice the voltage drop to 11 volts and not rise what so ever.

Question: How can I test the new alternator is working? I tried testing the voltage at the wire from the pcm to the connector but that gave nothing unless it's a ground??. The battery is showing 11.36v when running. The wire at the back, is that power or ground?

Anyways any help is appreciated, thanks.

 

The fatter red wire, the one that bolts to the rear of the alternator, is the output. Positive (red) test meter wire to that and negative test meter wire to ground. You should be getting a reading of 14-14.2 ish volts.

 

Well, I made a 10 gauge jumper wire from the battery to the alternator keeping both wires connected and still not getting a charge.

The connector going to the alternator, that is just a single wire, right?
What else could it be? I'm going to install the old one again to make sure.

What a nightmare! My clutch was easier to change than this! lol
This will be the 4th time removing the alternator and the 2nd switching around pulleys..

 

with key on you should have power to the small wire that goes to the alternator. with key off there should not be power to the small wire. it tells the alternator to start working. if it had power all the time it would drain the battery when the engine is not running.

 

Right... according to this diagram should be hot with key in "Run". Either a straight power or supplied by an output from the PCM depending on the vin number at least thats what it looks like. Either that or they both use the pcm and there were 2 different wire types. Not sure what the are showing in the brackets there. Either way you should receive battery voltage there.

 

Thanks for the input! I just tested that wire from the pcm to the connector. It put out the same voltage as my battery when I turned the key forward, so that's a good start.
I wonder if the pins are the same. It's an Delco 8242.

 

I was reading up on something about a dummy light for the alternator burning out?
Any ideas on this?
Also, is there a ground anywhere or is it just grounding through the body?

 

Did you put a meter on the alternator yet to determine how many volts it's putting out? That's step ONE.
Your jumper wire test does absolutely no good if the alternator isn't charging.

 

what are the part numbers for the new alternator? like 69 is sayin test the volts at the big wire on the alt while motor is running. if volts show same as at battery (11 or so volts) then its not working. should show 13.1-14.5 volts.

 

Oh i misread... i thought the output from the alt was what he measured earlier....