# Charging / Alternator problem



## BFGW (Aug 21, 2007)

I have bought a 1985 300 ZX which has a charging problem. Right after start, voltmeter shows full charge 15+ volts. A few seconds later, it stops charging and displays battery voltage. After a few minutes running time 3 to 5 usually, charge resumes and from then on, for most of the day it acts normally. Next day, or if standing a few hours, cycle repeats.

I have had the alternator tested and it checked out OK, putting out full voltage for about 3 minutes without failing. Have also checked the wiring, fuses, etc. 

Would appreciate any help / suggestions / ideas. This is the only problem left to resolve before I can enjoy driving the car.

Ben Gilbert
Miami, FL


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## Zen31ZR (Mar 24, 2004)

Sounds like the rectifier has some issues. Unfortunately it is located inside the alternator and so it has to be replaced as a unit. Sounds like you covered all the other bases, replacement is the only thing left. 

Most defective alternators, and even starters, test out OK on a bench or even with test equipment hooked up, because they are not actually under driving or starting load conditions.


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