Uugh, electrical problems...
 

Rather ubruptly, my 87 3.2 has developed an electrical problem. The 2 year old battery which has never once had a problem, now will not start the car. I had the alternator redone last summer as the alternator light started pulsing, but since then no problems.

First the alternator does not illuminate once the car is running (from a jumped start) and is registering 12.95V while checking across the battery. Before the start it was reading 12.00V. I checked the following morning and the battery read 11.87V and this afternoon at 11.85V. What's up? If it's draining, it's draining very slowly.

Thanks,
Michael

Batteries sometimes don't last very long (in my chequered experience with them).

12.00v is pretty dead (should be 12.5 ish). I you have a charger you should give it a full recharge and see if it holds it.

12.95v when car is running is too low an output for the alternator as well (should be 14.4ish). I think you might need to get the alternator and regulator checked (and may need a new battery too).

Battery load test
 

If you take your battery to a shop to load test it, make sure that it is fully charged before testing. Testing is done with a VAT (voltage-ampere test). The amount of load is based on the amp-hour rating or the cold-cranking amp rating. The battery is loaded at 3 times the amp-hour rating or 1/2 of the cold-cranking amps for 15 seconds. Battery voltage should be at least 9.6 volts. HTH.

dood

while the car is running test the voltage between the positive and neg batt terminals,, then check it between the pos terminal and a frame ground or some other good ground. i just did the same thing to a car yesterday and all it was,, was a bad ground strap.

I hope that helps you!!

LATE-ER

Kyle
71 911

Thanks - guys! Will definitely try to the ground strap test.

Michael