Voltage guage jumps when load applied??
 

I posted a thread last week about no charge when under load, i had one alt that was dead. I have replaced it and have 14.58 on both alts. My question is this, when i turn on my blowers or docking lamps my starboard needs will jump down and come back up. It has always done this but the port guage don't jump at all, Im thinking all the accessories are tapped into the starboard starter Hot lug. I always run my batt switch on all so it will charge both batteries, this should tie them together but don't seem to effect the port guage. What does other twin engine boats do?? Just curious?

no body has twin engine boat with twin volt guages??...Really.

you should not run the battery switches on ALL..you should run Port on 1 and starboard on 2..

as far as your gauges jumping ..you need to supply a good 8 gauge ground wire to the dash area with a bus bar and tap the ground to your gauges of that..PowerQuest did a poor job on the dash wiring..Had 3 290s and I had to do that to all 3

what gauge wire is the ground going up front, I've been in there and there are some pretty big ground cable, but no bus bar, just all crimped together looks like. Why not run batt switch on all?? I want both cranking batteries getting charge when running?? I have always done this on all my boats?

batt switch clarification...cranking batts are wired into switch one is on 1 and the other is on 2, I select all when im running so both will get charged!

when you put both switches on ALL you now have 2 alternators charging each battery..you dont want that.

My Fountain has the dash power and acc being feed off just the 1 motor. The other motor does nothing but charge that battery. Sounds like yours is the same way. Easy to check
Turn off 1 motor at battery switch and see if your dash and all acc work. If not, switch the other motor on and 1st one off. recheck.
I don't think it would be a good idea if both motors/alts/batteries are tied together feeding all the acc combined. In therory it sounds best, but you can create conflicts, esp with efi motors.

You only have 1 switch total?

Keep each motor on its own battery all the time. Each motor will charge the battery it is connected to thru the switch. No dead battery this way. And no conflicts

I only have one switch position 1-2-all or off. If i only switch to batt 1 or 2 the other will not see charge...right?

the correct way is to have 2 switches..

all my boats in the past had 1 switch, how is this incorrect?? It has the switch that was installed at the factory