Low voltage on glass dash...

[TcR7]

I have been having issues with “low system voltage” displaying on the right hand Garmin, and last night it displayed on both screens. Voltage gauge on dash still displays 13.6 or so. If I switch to “emergency” on the ACR SWITCH the message goes away...

[tbully]

I imagine "engine voltage" is the charge voltage measured off the alternator while "unit voltage" is what the Garmin itself sees off the B+ line. However, as you're probably alluding to, these really should be the same/similar.

Unless:
1) There's an unforeseen load somewhere
2) A battery is low/bad pulling the bus down (similar to "1", I guess) while trying to take a charge
3) ACR is doing something funny like charging the non-live battery while leaving the accessories on the other (not entirely clear how ACR works)

Your boat isn't in your sig. What are you running?

Just some initial thoughts as I subscribe to this thread. Good luck.

[TcR7]

thanks tbully,
someone suggested to replace the ACR switch with the old "1,2, ALL" battery selector swtich.
2018 R7 380vp

[Big Block Power]

No I wouldn't do that. But I would be checking voltage with a meter to see where you are losing it. Could just be a poor connection. Just have to find it. How far is the dealer?

[Bfun220]

I wouldn't start buying parts. Like BB said, could be just a loose/bad connection. You could remove the ground on the ACR, or remove the power wires to it and see if that was it.

[BobRae99]

This boat has to be under warranty. What does the dealer say about it?

[greenhut]

Best guess is you have a very low battery that is preventing the ACR from combining and charging it. Did you leave the batteries in the boat over the winter?

The ACR solution is far superior to the typical A/B/Both - dont change it! Ideally, measure voltage on both batteries before starting using a multimeter - if either is under 10.8V the ACR will not combine loads. Watch the voltages carefully after starting your boat and report back on what you see in the first minute on the voltages. After starting your boat, once the ACR sees 13.6V on either connection for 30 seconds, or 13V for two minutes, it will combine your batteries so both get charged by the alternator. If you can see the ACR, you will see a solid green LED indicating the batteries are combined. You can usually hear the change (yes hear!) about 30 seconds after starting the boat when the batteries are combined.

Switching to "emergency" is essentially the same as the ACR combining batteries. Since switching to emergency makes the alert go away, it sounds like your ACR isnt combining. Again, this is most likely because one of your batteries is very low (<10.8V). You can try running the boat for a while on emergency to try to charge up the low battery. One other thing to check is that the ACR has a good ground connection - perhaps it pulled off.

[tbully]

Best guess is you have a very low battery that is preventing the ACR from combining and charging it. Did you leave the batteries in the boat over the winter?

The ACR solution is far superior to the typical A/B/Both - dont change it! Ideally, measure voltage on both batteries before starting using a multimeter - if either is under 10.8V the ACR will not combine loads. Watch the voltages carefully after starting your boat and report back on what you see in the first minute on the voltages. After starting your boat, once the ACR sees 13.6V on either connection for 30 seconds, or 13V for two minutes, it will combine your batteries so both get charged by the alternator. If you can see the ACR, you will see a solid green LED indicating the batteries are combined. You can usually hear the change (yes hear!) about 30 seconds after starting the boat when the batteries are combined.

Switching to "emergency" is essentially the same as the ACR combining batteries. Since switching to emergency makes the alert go away, it sounds like your ACR isnt combining. Again, this is most likely because one of your batteries is very low (<10.8V). You can try running the boat for a while on emergency to try to charge up the low battery. One other thing to check is that the ACR has a good ground connection - perhaps it pulled off.

Very insightful. Thanks for sharing this, greenhut.

[Big Block Power]

Good info guys. Let's get some voltage feedback now

[TcR7]

Thanks greenhut...good info.