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R7 acting a little weird
Posted: Sun Jul 27, 2025 6:55 pm
by Dadof3girls
So just recently, my navigation/instrumentation screens have sometimes not worked. They either don’t fire up after I turn my key to on, or they have just gone out while driving. They usually fire back up on their own within 5-10 minutes. This weekend, a couple of times, my stereo didn’t want to turn on. Eventually it did, but it did it on its own time. Sounds like an electrical gremlin, but just wondering if this could be battery related. My battery’s are probably 3 years old.
Re: R7 acting a little weird
Posted: Mon Jul 28, 2025 4:11 pm
by jhnmdahl
Sounds like a low battery voltage to me, that gets charged back to acceptable levels temporarily once you've run it for a bit. I'd certainly start by measuring battery voltage, or better yet, take the battery in to a shop and have them test it.
Re: R7 acting a little weird
Posted: Mon Jul 28, 2025 8:12 pm
by Dadof3girls
jhnmdahl wrote: Mon Jul 28, 2025 4:11 pm
Sounds like a low battery voltage to me, that gets charged back to acceptable levels temporarily once you've run it for a bit. I'd certainly start by measuring battery voltage, or better yet, take the battery in to a shop and have them test it.
Yeah I was thinking the same about getting the batteries tested to at least rule that out, if it is something else. I have also had electrical issues at my dock, and I really don’t know how much my batteries have been charging when I plug it in. I have a feeling they are not charging properly, and hoping it is just a battery issue.
Re: R7 acting a little weird
Posted: Tue Jul 29, 2025 10:30 am
by stifflkd
Do you have glass panels? If so configure them to display both batteries.
Re: R7 acting a little weird
Posted: Tue Jul 29, 2025 3:55 pm
by bruceb58
Not likely your batteries if you are able to actually start your engine. Sounds more like an intermittent power connection issue. Have a video of what happens?
Re: R7 acting a little weird
Posted: Tue Jul 29, 2025 8:53 pm
by Dadof3girls
stifflkd wrote: Tue Jul 29, 2025 10:30 am
Do you have glass panels? If so configure them to display both batteries.
I do have glass panels. Not sure I have ever messed with batteries on them though.
Re: R7 acting a little weird
Posted: Tue Jul 29, 2025 8:59 pm
by Dadof3girls
bruceb58 wrote: Tue Jul 29, 2025 3:55 pm
Not likely your batteries if you are able to actually start your engine. Sounds more like an intermittent power connection issue. Have a video of what happens?
I have no problems starting the engine at all. The engines will run, but just sometimes the screens go blank.
Only other thing I didn’t mention is last year a couple of times when it rained, basically the electrical shorted out. The screens would work, but it wouldn’t go into gear. Once somewhat dry, I had no issues. I never solved this issue, just avoided rain. Not sure if any of this is related.
I will try and take a video this weekend if the screens go blank.
Re: R7 acting a little weird
Posted: Wed Jul 30, 2025 10:26 am
by jhnmdahl
I agree with Bruce - this is sounding more and more like a bad connection somewhere that occasionally goes open. I'd go through and clean the battery posts, tighten all the wiring on the ground block, etc., and check the wiring behind the dash for loose cable connections. A bit of work, but at least it's free to try.
Re: R7 acting a little weird
Posted: Wed Jul 30, 2025 10:53 am
by tgernst
As said previously, you mighty want to check the tightness of the screw terminals on the ground bars located both fore (under the front seat behind the access panel) & aft in engine compartment. I was able to put nearly a 1/4 turn on every screw I touched on my R4. I discovered this while replacing a bilge pump. This could create intermittent power issues real easily.
Re: R7 acting a little weird
Posted: Wed Jul 30, 2025 2:20 pm
by Dadof3girls
tgernst wrote: Wed Jul 30, 2025 10:53 am
As said previously, you mighty want to check the tightness of the screw terminals on the ground bars located both fore (under the front seat behind the access panel) & aft in engine compartment. I was able to put nearly a 1/4 turn on every screw I touched on my R4. I discovered this while replacing a bilge pump. This could create intermittent power issues real easily.
I will check this weekend if I understand what you are saying I should check. What exactly are the screw terminals on the ground bars? Sorry, I just don’t know what I should try and tighten.
Re: R7 acting a little weird
Posted: Wed Jul 30, 2025 3:28 pm
by tgernst
Silver bars maybe 1" wide 8" long where all the yellow wires terminate. Since it is your displays. I would check the ones behind the access panel in front of the cockpit dash first. I was surprised with mine that a boat with < 20hrs had so many loose connections. QC must have had the day off.
Re: R7 acting a little weird
Posted: Thu Jul 31, 2025 12:40 pm
by WhamiltonJr68
There is a relay behind the helm for the Garmin screens. Lift the seat on the bow starboard side to access the relay. Mine screens would start the day running great. After an hour of running we would stop & turn off the engines. Screens wouldn’t immediately power back up. Eventually, they would come back to life on their own. The relay was overheating. New relay & screens work all the time. 2020 R7
Re: R7 acting a little weird
Posted: Mon Aug 04, 2025 5:11 am
by Anchor86
We just had same issue with our `20 R7. We replaced the blue sea automatic charging relay (ACR) box mounted behind the battery switch. It automatically adjusts voltage between the 2 batteries. $65 and easy to swap out . I swapped the relay out prior to this and still had displays going out and fosgate head unit displayed “low voltage”. 4hours since new ACR and all is good.
The following is from our cobalt dealer:
On Garmin display have unit voltage and engine voltage displayed. You can’t diagnose the switch unless you can test the voltage on the batteries when the engine is running. With dual Garmin screen screens and you should be able to view the engine voltage and the unit voltage. If the unit voltage is coming up to over 13 with the engine voltage while the engine is running when the switch is in the ON position, that means your automatic charging system is working properly. If it’s not, then it’s not working properly and I’d recommend you run the boat on combine until you get that part repaired.
Re: R7 acting a little weird
Posted: Mon Aug 04, 2025 3:11 pm
by Norris_Boating
But if it is the radio too, I would think it is the battery. You have two batteries, one is for your engine to start and the other runs your Garmin and Radio. When you turn the boat battery on do you turn both on? Try swapping battery one with battery two, I wonder if the boat will have Garmin's but struggle to start. Get a volt meter on the batteries when the Garmin's/radio won't work, see if one is around 10 or below.
If you look through your Garmin options you can put the voltage of both batteries on your display. Again, since it is both the Garmin and the stereo, I would definitely be looking at the batteries.
Re: R7 acting a little weird
Posted: Mon Aug 04, 2025 3:15 pm
by jhnmdahl
Anchor86 wrote: Mon Aug 04, 2025 5:11 am
We just had same issue with our `20 R7. We replaced the blue sea automatic charging relay (ACR) box mounted behind the battery switch. It automatically adjusts voltage between the 2 batteries. $65 and easy to swap out . I swapped the relay out prior to this and still had displays going out and fosgate head unit displayed “low voltage”. 4hours since new ACR and all is good.
The following is from our cobalt dealer:
On Garmin display have unit voltage and engine voltage displayed. You can’t diagnose the switch unless you can test the voltage on the batteries when the engine is running. With dual Garmin screen screens and you should be able to view the engine voltage and the unit voltage. If the unit voltage is coming up to over 13 with the engine voltage while the engine is running when the switch is in the ON position, that means your automatic charging system is working properly. If it’s not, then it’s not working properly and I’d recommend you run the boat on combine until you get that part repaired.
This makes a lot of sense, and wouldn't have been on my radar immediately as a cause of low voltage. Thanks for chiming in!