I purchased and installed a new humminbird 777 sonar unit but I am recieve a "Low voltage imput" message on my screen. I have checked the voltage from the power supply on the boat and it reads 12.5v, I have also checked the voltage from the prongs of the provided power supply lead I got from humminbird it also read 12.5v. But, when I put on the head unit of the sonar its diagnostics says that it is only recieving around 10v.
Has anyone else ever encountered a problem like this? Do you think I have a bad head unit or do I have something else going on?
I'm stumped it appears to be working properly other than that darn "Low Voltage Imput" message that keeps popping up.
If anyone has any ideas please let me know.
Thanks, Brian
have had same problem with a 141c. seems to come on after a few hours...no other problems like u said but message comes up and starts flashing?
Do you have the unit wired directly to the battery and not you fuse panel? All Sonar and GPS units must be wired all the way back to the battery. Other than that I can not think of anything. Could be a bad unit.
Quote from: MadWags on May 18, 2008, 04:06:34 PM
Do you have the unit wired directly to the battery and not you fuse panel? All Sonar and GPS units must be wired all the way back to the battery. Other than that I can not think of anything. Could be a bad unit.
I have it connected to the fuse panel, because that is what is the 1st option it gives you in the installation manual. If I have 12.5v at the plug of the power supply how could I lose 2.5v just by plugging it into the unit?
Problem fixed!! I followed Madwags advice and connected it directly to the battery. Now have a constant 12.2 volts. Thanks for the tip, you saved me from my headache.
There could be a couple of reasons why you got a low voltage message. First and foremost when you are connected to the fuse panel the unit could be in series and that would cause a low voltage reading. If connected in parallel, then you would have 12 volts all the time. The other reason is a bad ground. I have a Hummingbird 565 and had the same problem until I connected directly to the battery. I did put a fuse in line with the hot side so that the unit would be protected from any surges. GPS units and fish finders should be connected directly the battery with a fuse in line on the hot or positive side.
BD ;D
You can run them either way--accessory buss panel or direct to the battery. All of my units (787, 997, and 1197) are connected to the accessory buss panel and I get no Low Voltage readings. All that message does is let you know the power to the unit has dipped below 12v. It is in no way a defect to the unit. In fact, I think some of the new production units going forward have eliminated that message from the programming. As far as what causes it, some of the other guys touched on it. Since other accessories and switches on the boat are wired into that panel, you can get an intermittent low voltage when those accessory switches are turned on. I've also heard of it happening when the ignition key switch is turned on, especially if the crank battery is somewhat low since the outboard pulls a lot of juice at one time when you start it.
Glad I could help. Make sure you put an inline fuse on the positive side as suggested. Check you owners manual for size. All Lowarance units come with the inline fuse and are recommended to be wired directly to the battery, NOT the fuse buss. I am not familiar with Hummingbird but obviously they like it too.