I have two batteries and a Blue Seas manual switch. When the starboard side is on I get good voltage to the dash and engine. When the port side is on I get almost nothing at the dash and will not turn over the engine. A vom at the battery reads 12.4 volts. All connections at the switch are tight and corrosion free. Where do I go from here, please?

Padraig

Not saying this is the issue but do you have the blocks grounded together ?

Single engine boat, Velocity VR 1

Padraig

so, back of switch at connection posts…..bad side still shows 12.4 volts ? But cable out post (one to starter usually) shows what when bad side switched on ? If low like your gauge this shows bad switch.

12.4V is only about 75% charged. Leave volt meter attached to battery while cranking and see what it reads. It shouldn't drop below about 10V

ooops

SB I get good voltage at both inputs...when switched on nothing at output terminal. Therefore bad switch??? I assume better to replace them disamble and try to fix? Any thoughts on better switch?

F-2 Speedy Not your fault...I should have described boat. Thanks!

snapmorgan Does notcrank...Thanks

Padraig

Out put term must show something when switch is on the side that makes your guagescwork and starter engage. Right ?

I use Amazon for reviews. Lots of good info buried in there. The Blue Seas switches have fallen apart internally on several peeps. None that i can find find with the perko’s.

Blue Seas:

perko:

Battery switches can go bad, but my money is on one of your batteries has an internal failure. Perhaps a dead cell, open circuit, or loose terminal somewhere.