Ok i have a bone stock 1992 350 B4c Xcop car, the alt. is 5 months old puts out 14.0 volts at idle but when driving will drop to 8 or 12 or 10 it dosent seem to have any rime or reason, i took off the pos. side of the battery to check for a draw and it showed a 12.8 v "draw" so i took off all the relays on the fire wall with no change, disconated all fues and no change, cleaned neg, ground on block no change, disconated the fuel pump under the car and no change, dis. the alt both wires and no change? I heard the fuel pump prime with the key not in the car? please help

 

12.8 is battery voltage... thats not a draw. electrical draw is measured in amps. if you use a multimeter switch it to direct current amps. then switch the plug from ohms/volts over to the com port. disconnect the +ve battery terminal then put one of the multmeters leads on the +ve side of the battery and the other lead on the +ve battery wire. chances are you alternator is pooched... your reading should be in milliamps i cant remmeber off head whats acceptable, depends what you have in your car though aswell

 

thanks i will try this, a i thought i was heading down the wrong road..

 

ok what should i see as far as a draw? what is ok? the car is all stock and i have a stock radio?