Low Voltage at Fish Finder Display

[jpell]

I have been having issues with my radio "rebooting" spontaneously 3 or 4 times over the course of a fishing outing. Had several mechanics look at it; nothing found. On my last outing the fish finder shut down and would not restart until 30 minutes later. I called tech support for the Lowrance Gen 2 HDS Touch and he said it might be a low voltage issue. I adjusted the display on the fish finder to include a voltage at the unit reading on the screen and it reads 9.3. This seems low to me and was with the outboard running; 2015 Yamaha 150.

Question: what should the reading be? Where do I start to look for the issue?

 

[Scott Danforth]

Should be about 13.2 volts with motor running

 

[GA_Boater]

Yeah - That's way low.

Start at the battery and measure what motor is putting out while running. If you have the 13 volts or higher as Scott said, then start cleaning connections, including grounds.

If you aren't getting 13 volts, you have to look into the motor charging system. But I bet it's the wiring with a newish motor.

 

[dingbat]

Been down this road before. First off, don’t rely on a voltage readout on the fish finder for troubleshooting purposes.

Case in point....9.3 volts is a dead battery. Motor wouldn’t turn over let alone run with with the reported voltage.

Chased an issue a couple years back where I had 12.7 at the connector and 12.0 on the display.

Called tech support to discuss the issue. Long story short, voltage taken of regulator pcb not raw input. What good is that?

Check voltage at fuse box and at back of unit. Should match battery voltage

Check inline fuse. Notorious for causing problems.

 

[Bondo]

Ayuh,.... Sounds like corroded wirin' connections to me, possibly a bad ground path,.....

 

[jpell]

Awesome responses, thank you very much for your recommendations. I will let you know what I find.

 

[jpell]

Spent some time tracing wires, all look corrosion free and secure in their connection. Went and bought a multi-meter, went to YouTube to learn how to use said multi-meter, checked one battery and it read 12.79. checked the other and it read 9.70.
My boat has an ACR system. 2 batteries and a monitor that charges as needed. Mechanic said no "house' and "motor" battery anymore. The house and motor can use either and the ACR monitors and charges as needed. Number two battery bad?

 

[jpell]

Ok, so I am learning as I go along...
Checked voltage at both batteries; battery #2 was low.
Looked at fuse block, same voltage reading as battery #2.
Looked at ACR and triple light flash indicating "under voltage isolation". Really hard to see in the sunshine...
ACR saw a problem and isolated that battery from motor and charging system?
Battery #1 IS FOR MOTOR.
Battery #2 IS FOR HOUSE.
Next I pull battery #2 and have it tested...

Thanks for your patients.

 

[jpell]

Pulled battery #2 and took it down to NAPA. They said, "low voltage, charge it and bring it back". Ran into a mechanic friend and shared my woes. He said it sounds like the ACR is not charging the battery. He recommended re-installing the battery and start the motor, run it up to 2000 rpm and use the multi-meter to see if battery #2 is receiving a charge from the ACR. Did so and the battery never went above 10.1 amps after 10-15 minutes of run time. So now I am charging the battery on a trickle charger to get it back up to normal range. I will then see if the ACR switches off of the "under voltage isolation" mode.

Question: When the ACR is in the isolation mode, does it still send a charge to the battery? I am wondering if, hypothetically, I left the battery switch on over night and the fuse box drew down the battery to a point where the ACR "isolated" it.

You mechanics out there must be enjoying this....

 

[GA_Boater]

Question: When the ACR is in the isolation mode, does it still send a charge to the battery? I am wondering if, hypothetically, I left the battery switch on over night and the fuse box drew down the battery to a point where the ACR "isolated" it.

No. Look at the trouble shooting chart, it's saying to charge the low battery and failing that - Replace the battery.

 

[sam am I]

So now I am charging the battery on a trickle charger to get it back up to normal range. I will then see if the ACR switches off of the "under voltage isolation" mode.

Yes, but!! Only as long as it holds a charge (the battery is still "ok") and the battery's "resting" voltage is remaining above the "under voltage lock out threshold" of the ACR. Not sure what that is, depends on the manu and Blue Sea has changed it a few times now, think its around 10.5 to 11V, not sure, you'll have to look it up.

Question: When the ACR is in the isolation mode, does it still send a charge to the battery?

No, not to the house battery. Yes, to the motor battery.....

I am wondering if, hypothetically, I left the battery switch on over night and the fuse box drew down the battery to a point where the ACR "isolated" it.

Yes, you most likely left something on in the house circuit side and have dis-charged the house batt down so far that the ACR locked it out of the charge circuit............This is the fickle part of an ACR/VSR and based on my needs, I don't particularly care for as it can't isolate(like exactly and simply what you're having to do right now with the trickle charger) and charge JUST its aux/house batteries, it can only parallel them to charge.......arrrrg!!.

Hence, it knows better/is designed then not to parallel your/a very/ish discharged battery with your/a good motor battery..........Current inrush at parallel time/wiring would go off the charts.

You mechanics out there must be enjoying this....

Not a mech but, I do have a few wrenches .......At least you're asking and trying to learn, its all good man, np.

 

[jpell]

Ok. Went out this morning. Battery was on trickle charger all night and read 13.4. Checked the ACR and the isolation light was still flashing three times. Started the motor and turned on the fish finder. Voltage read similar to multi meter. Ran motor for about 20 minutes, “Under voltage isolation” code continued to flash and you could watch the voltage drop on the fish finder to 12.5 after 20 minutes.

 

[sam am I]

As per Blue Sea LED chart (assuming that's what you have).....

Blinking slow = "Isolated Start engaged".

Blinking fast is "Isolated Under Voltage Lock Out"

Two different beasts...........You have both occurring?

Hard to tell from here but, if the house batt (and the motor) was above the lock out voltage as it appears you did AND the alt is charging normally and it still didn't combine, then either........

1) You have the "Isolated Start Engaged" signal from the ig. switch stuck on, hence a continuous slow blinking LED

or

2) The ACR has crapped the sheets

Assume also you've clean and checked all connections to eliminate that as a possibility

 

[jpell]

Yes, all connection are good. Triple flash is the error code but even with both batteries charged and good; I had them tested, I can’t get the ACR to go back to normal operation.

 

[sam am I]

ACR is toasted sounds like, and yes, triple flash is UVLO code............Blue's Rev 11 I linked above didn't state the three flash code sequences anywhere in the doc but, Rev 9 (below) does, guess you have an older ACR eh?

How weird, wonder if then the newer ACR's (Rev 11 on) don't have the three LED diagnostics like the Rev 9 ACR's since they pulled out those specifics on flashing codes of their latest Rev 11 doc's? Just "slow and fast" LED flashing rates now I reckon? Hmmmmmmm, oh well, nother change I guess............

If you're in the market for something new, and better IMO (although Blue Sea still makes high quality stuff, lets not forget they're a 420 proud state as well ), I'd recommend this over an ACR/VSR simply due to it's much smarter and best practice battery charge management IMHO.

I've ran one (1 alt, 3 batts type) now for going on 4 seasons on my fishing boat, no prob's yet. No need to have pulled out a battery and/or manual isolated it to charge/test it, this thing can do this for you automatically and more.........

 

[dingbat]

Ok. Went outStarted the motor and turned on the fish finder. Voltage read similar to multi meter. Ran motor for about 20 minutes, “Under voltage isolation” code continued to flash and you could watch the voltage drop on the fish finder to 12.5 after 20 minutes.

Something isn’t right here.

The fish finder shouldn’t drop a healthy battery 0.2 volts in 20 minutes.

I assume the battery was load tested?

 

[jpell]

Yes, battery was load tested. Before replacing ACR at $80, I called Blue Sea Systems tech support. Very helpful folks. Walked me through diagnostics and identified a bad circuit breaker between ACR and battery #2. It is also from Blue Sea Systems. Sending me a new one, gratis!

I tried to upload a photo of the system but it says it is too big.

Thank you all for your help!

 

[dingbat]

Walked me through diagnostics and identified a bad circuit breaker between ACR and battery #2.

You have actual circuit breakers between the switch and battery? I have in-lines fuses.....

 

[sam am I]

bad circuit breaker between ACR and battery #2

Geeeesh, that one flew right by me, never even thought to consider an open there........Dang, makes sense now looking back (20/20 hindsight is always so clear ya know) how the ACR was reporting the problem. Glad ya got it and thx for closing up what the fix was, will def help ppl later on down the road, I'm sure.

Not sure what type of C.B. you're using but, if it flaked out because of marine corrosion etc, these work well, I've ran a few in my boat now for a few years and have had good luck so far, they're Ig. safe and waterproof of course and they aren't too expensive either

View attachment bus-ele-cat-5084-full-line-retail.pdf

 

[sam am I]

"Maine rated" here