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

if you have a twin engine boat with two batteries the correct way to wire it is with two switches

PowerQuest is know to built good strong hulls...wiring is another story

X2

I have a slight issue with my volt gauges too... Mine just don't read properly. Bad connection, bad gauge, or bad ground? I test the alts at the hot wire coming off of them and it's 14v+, the gauge reads 10v, both batteries are brand new. I even upgraded and replaced on alt and upgraded the hot wire to an 8 gauge wire. Suggestions? I'd just like the gauges to read right, so I know if I ever really have an issue.


While we're on the subject of battery switches... Does anyone use a battery isolator? And are they worth while? I had an issue last season with one of my batteries being bad and killing the other. Would an isolator fixed that issue?

I can't grasp the idea of having two batt switches and be able to do the same thing i can do with one, i can select or deselect each individual batt. Can you draw me out a diagram so i can better understand the use of two batt switches. I probably will run the new ground circuit but probably not gonna change the complete batt cable set-up for everything is already ran, cut to length and routed very nice??? Dont mean to me a hard-head just don't see how two is better than one. If you have two batt switches, are they just on/off? My guages seam to read correct though, thats not the problem, just curous why both don't jump....only starboard. The wiring harness comes off that engine, I have followed it back, it don't run over to port...(dont look like it)?

wjb21ndtown...sounds like you have high resistance in ur guage circuit...probably high voltage drop somewhere? I would pull ur ip and look for some crimp connectors that are corroded...

You have two motors and two batteries. One battery for each motor. They are separate. Each battery should have its own switch. If one battery is low or dead you can turn that switch to both or all and pull from the other side. By running on "both" for an extended period you will ruin an altenator.

I just had to replace one alt cause it was dead! Im looking at the blue sea dual circuit plus batt switch, this will keep them seperate but give me the option to combine if needed. I think this switch has four posts so I don't have to change all my cables around, just refigure them on the back..

That's the switch you need. Simple and does the same thing as 2 switches. I installed one in my cruiser do to it's simplicity.

ordered it today via amazon @ 43.95 Its on the way. Thanks guys!