1989 340 Sundancer electrical question

[Bullfrogboatman]

My Stbd bank of batteries will not charge from Stbd alternator(just rebuilt, so I know it works), or the generator.
Shore power charges them just fine. I checked the grounding lugs and they appear fine.
Also, my stereo shuts off when I blow the horn.
Any ideas would be appreciated.

Pete

 

[rondds]

Pete
How old are the stbd batts. If they're stone cold dead you could probably run stuff off of them while the charger is on, but maybe not when the engine is running?

A horn is almost a dead short and draws an awful lot of power. I'm guessing one or both of the stbd batteries are shot. Disconnect them from each other and measure the voltage after a day or so off the charger and see what the voltage is.

Batts in parallel should be replaced at the same time b/c one weak batter will fool the charger into providing voltage and will fry the good battery by overcharging.

 

[boatmailster]

when batteries are low or bad any load on them cause voltage drop, and clarion stereos shut down with voltage 10-10.5V (not sure about exact value)