bs951

After cleaning the engine bay with hose, I've been chasing low voltage. I thought some components got wet and needed time and heat to dry out. But that hasn't been the case.

Initial voltage readings:
At battery with engine off - 13
At battery with engine running - 12.3
At alternator - 12.1

I then removed battery and cleaned grounds. Replaced alternator with rebuilt Bosch unit. Replaced engine to chassis ground strap. Put full charge on battery.

After voltage readings:
At battery with engine off - 13
At battery with engine running (>2000 rpm) - 12.2
At alternator - 12.1

The ! light and voltmeter warning light are both on with key in ON position.

I'm stumped on next step(s).
Would a phantom electrical drain cause these numbers?
Instrument cluster?

Thanks for your input. Cheers

Brad

ddombrowski

The first thing I would do when chasing a non-working alternator is run a jumper wire from the + alternator post straight to the battery and a jumper wire from the alternator housing straight to the neg battery terminal.

If this corrects your voltage, you have a wiring problem. If not, then the alternator or voltage regulator is bad.

If it is a wiring problem, try the two jump leads one at a time to determine if the problem is a ground fault or if the problem is a power lead fault.

bs951

Found the culprit. H4 conversion ground wire was connected to the alternator neg post. Removed and now getting 14.2 with engine running.

The H4 conversion was done by PO. Where is the best place/location to ground H4 system?

Thanks