Chasing a gremlin.

[sixohfour]

Lowrance HDS Carbon 9, about 2 years since I bought and installed aug 2018. Seems to work fine the year it was installed, second year we only used the boat a couple times due to engine rebuild. Late tHe second year, the couple times we got out, it started to act up. This summer I’ve been playing with it, seemed to work fine anytime I was tied up and playing with it, but would only last about 30 min or so while underway, before it started flickering. A couple weeks ago, when returning from a day trip, on one of the last flickers, a saw a white halo around the edges of the screen, then it just shut off and I couldn’t get it to come back on.

Pulled the unit and sent it to HC for testing and possible warranty, they plugged it in on the bench and said it worked fine.

I have it back on the boat now and it will power up, but still flickers. HC sent me a new power cord, tried that, but no better. Replaced the fuse, same. Checked all connections back to bus bar on bridge, all solid and in good condition. Multimeter shows steady power at bus bar connections. Worked my way towards unit testing with multimeter and all seems good until I get to the plug that goes into the back of the unit, assuming I am testing the correct pins, it does not show steady current. Any thoughts?

 

[GLG]

If it was my boat I would string a new temporary wire from the common ground (negative) to the new power cord and see if that fixes the problem. If it doesn't work then you can take that same wire and do a temporary positive one to test that side of the circuit.
On occasion I have found that I still get 12 volts but it's the amps that are missing due to corrosion.

 

[gungadin]

Don't know if you remove your head unit when not in use, but if you do not, you need to put an isolation switch (a simple toggle switch is fine) on the power in line. If you do not there will always be a very small current flowing through the head unit. This will cause corrossion on those tiny pins and wiring, with subsequent voltage drop.

 

[Corey_lax]

Is it 12-13.5 volts that your reading? Overcharging? My electronics don’t like overcharging at 16 volts that my main puts out

 

[Gear'n'beer!]

Your main puts out 16v?
That doesn't seem right

 

[Chasin' Dreams]

Ya sounds like might be a voltage/amperage issue. Mine was doing similar things right before I had to replace my house batteries. Make sure your battery supplying the juice isn't getting weak during times of power draw. Even if it seems good while boat is running and charging it may not be holding proper voltage/amps when other items put more draw on the battery. Should have around 13.5 volt constant while running. And ya you could be losing juice like others have said through all connectors, pins etc.

 

[Corey_lax]

Your main puts out 16v?
That doesn't seem right

Mine does. Old two stroke unregulated. Once we’re running I make it charge two batteries and then it’s no worries.

I have a voltage regulator for it but have yet to put it in over the last 3 years haha

 

[sixohfour]

Ya sounds like might be a voltage/amperage issue. Mine was doing similar things right before I had to replace my house batteries. Make sure your battery supplying the juice isn't getting weak during times of power draw. Even if it seems good while boat is running and charging it may not be holding proper voltage/amps when other items put more draw on the battery. Should have around 13.5 volt constant while running. And ya you could be losing juice like others have said through all connectors, pins etc.

Well, after much troubleshooting and several trips to Lordco, I gave up and moved on to the next job, replacing house batteries. It turns out the Lowrance unit is very sensitive to weak batteries. After new batteries were in, the unit seems to function properly. Thanks all for the comments and suggestions, I learned a bit on this thread. Cheers.

 

[ab1752]

Your main puts out 16v?
That doesn't seem right

That's exactly what I was gonna say, something funky going on and it seems like it's over charging. 13.2 ish is what my main charges and my 9.9 yamaha HT charges actually higher at 14.5, which may be something I should care about but havent yet.

Edit should have read the rest of the thread...

 

[Corey_lax]

That's exactly what I was gonna say, something funky going on and it seems like it's over charging. 13.2 ish is what my main charges and my 9.9 yamaha HT charges actually higher at 14.5, which may be something I should care about but havent yet.

Edit should have read the rest of the thread...

I have the regulator for mine. I’ll install it one day. One day.... along with all the other parts and pieces I plan on installing haha

 

[Chasin' Dreams]

Well, after much troubleshooting and several trips to Lordco, I gave up and moved on to the next job, replacing house batteries. It turns out the Lowrance unit is very sensitive to weak batteries. After new batteries were in, the unit seems to function properly. Thanks all for the comments and suggestions, I learned a bit on this thread. Cheers.

Right on great to hear.