Alternator repair

Tony Radford · #1 (**permalink**) 10-13-2011, 10:54 AM

Battery went from good starting turnover to bone dead in 45 minutes of steady driving. Battery checked out fine.

patrickt · #2 (**permalink**) 10-13-2011, 10:58 AM

Quote:

Originally Posted by Tony Radford

Battery went from good starting turnover to bone dead in 45 minutes of steady driving. Battery checked out fine.

Since you know your battery is good, and you know your 1-wire alternator is good, the next step is to performa voltage drop test along the charging circuit. Here is a diagram showing you how to do that: Alternator Voltage Drop Test

patrickt · #3 (**permalink**) 10-13-2011, 11:07 AM

Typical bad places that cause voltage drops are: 1) Grounds (both the alternator ground and the battery cable to the head/block), 2) The cables at the battery posts themselves, 3) The positive battery cable to the solenoid, you get the idea.... Lately there seems to be a run on "poorly grounded alternators" that rely on their ground via a painted, or powder-coated bracket and bolt.