voltage

 

12.5 volts I have not checked amps at all only voltage.

 

Not hounding you, but this part of your post "with the key off I checked the voltage at the battery on the negative and the car body and both were 12.5 I checked the voltage at the alternator and it was around 7 volts. What might cause this voltage drop?" I will try to help with what I can, but accuracey needs to be posted.

 

This is acurate I checked the voltage from +terminal to -terminal and from positive terminal to the body of the car. both were 12.5 volts. I check the voltage on the positive post of the alternator and it was 7 volts so somewhere between the battery and the alternator the voltage is dropping from 12.5 v to 7 v

 

as in the battery is putting out 12.5 v but the alternator is receiving 7 when it should receive 12.5 v. the wire from the battery is in a harnes so it is difficult to tell if there is an issue inside the harnes but I thought maybe it could be a ground issue somewhere else.

 

harness

 

Ok there is no + terminal to the body of the car. That would be - (ground). You should read from the battery + to frame - with the car running 13-14 volts. If you are reading 7 volts either you have a not good lead to VOM ground or a + vom to battery, I'd suspect bad ground on the VOM lead.

 

right.... I checked the battery+ to battery- with the VOM and I checked the battery+ to the frame- battery showed 12.5v and battery to frame showed 12.5v then with the car off I checked the alternator+ to the frame- and it showed 7v I have peeled back most of the harness casing and have found no shorted wires. The car will not run but will turn over(only tried this once). When the battery is connected nothing works except the service engine light is on with the key off and the headlights switch on. If you turn the key on the gauges are pegged out and no accessories work.

 

disconnect both battery posts, with a vom check voltage, and polarity.

 

correction the service engine light now stays on when the battery is connected