Well after finding my alternator was bad by testing it at the store (reading 12v and under on my volt meter) I put a reman'd unit on. Now here's the odd thing.

Without AC on or the lights I get a 13.5-14v reading
With the AC on I get 12.5-13v
With headlights and AC on I get just above 12v

Before I completed my reman'd alternator install I changed the battery fully. Now - what the hell is going on? I always thought an alternator should put out more voltage with accessories on in order to compensate for the extra load.

I tested the reman'd unit before going out of the store and it read where it should. So what's the deal?

 

Sounds like you have some resistance in the wire from the alternator to the battery, could be corroded at the terminal ect. If you have a ohm meter handy take the wire off the battery and the alternator and see what the resistance is between the both of them, it should be less than 1 ohm.

 

I don't have an ohm meter handy but I'll be looking over grounds on the car tomorrow.

 

I removed the battery today in order to clean around it (there was tons of stuff in there). I cleaned the negative ground from the battery to body really well with a wire brush, and cleaned up the terminals.

Here are the voltages at the battery:
Running - no headlights/AC: 13.8v
Running with AC: 13.4v
Running with lights: 13.4V
Running with lights/AC: 13.1v

Does anyone know of where some other grounds are to check? I know those numbers aren't bad per se, but i would rather clean up all the grounds to see if it will sstabilize.

 

my new capacitor says its 14.3 volts

it rarely dips below 13v even with headlights /ac and bass hitting

 

im at 14.4 but thats with a kinetik hc1800 powercell as a battery

 

Anyone know of any other grounds to check?

 

None that will inhibit the alternator from charging, time to check that power wire to the battery, and if that is ok maybe you didn't get the right alternator which is why its crapping out when you load it.

 

Now at the battery i get:

Idle - 12.7v
AC on 12.4
Lights on 12.4
Lights + AC - 12.2-12.3...

Yet at the posts on the alt I get:
Large post - 13.8V running
Small post: 14v running

I noticed the positive cable that bolts to the battery terminal has some wiring exposed but it does not look frayed



Anyone know where the positive cable runs from the alt?

 

More info - Voltage using the ground to the battery and the + post on the alt is the same as + to - on the battery