strange electrical issues lowrance is reading 6volts

[Bustedknuckle84]

I have some wiring issues, My lowrance downscan unit reads 6volts and barely turns on when my boat key is not in the on position. However, I confirmed that the +and - wire connections from the unit are getting 12 volts even down to the power source. However when the key is in the on position the unit turns off and has even harder time starting up.

THE CATCH: I moved the wiring to a battery by itself and the unit read and turned on just fine. so its not the unit or the unit's wiring thats messed up.

 

[Silvertip]

Re: strange electrical issues lowrance is reading 6volts

Do you have an I/O or an Inboard powered boat? With the key in the ON position but engine not running, the ignition system is drawing a fair amount of power (which is a good reason why the locator should NOT be wired to the ignition). Why sit with the key on, engine not running and the igntion system drawing a great deal of current? Does the unit operate properly with the engine running?. Do the gauges operate properly when the locator is acting up. The locator reads the voltage present on its POS and NEG leads. If it reads incorrectly the locator wiring connections are bad, the source of power feeding the unit is bad, or the battery is low.

 

[Bustedknuckle84]

Re: strange electrical issues lowrance is reading 6volts

Outboard, does not operate propely with enigne on, what is a locator please? The battery are good for sure just installed a brand new one. Gauges are ok, however the cd player stereo has a flickering power which is kinda wha the downscan unit is doing.

 

[Silvertip]

Re: strange electrical issues lowrance is reading 6volts

Fish Finders are Locators. Regardless what the manual says, fish finders do not find fish. They identify the presense of fish when they fall under the sonar beam. Just because you installed a NEW battery does not mean it is good, nor does it mean it was fully charged. Since the stereo is doing the same thing as the locator, you have power distribution problem. Does the charging system on the outboard work? What terminal on the ignition switch do you have the locator and the stereo connected to? If it is not on the "A" (accessory) terminal it is no wonder things aren't working.

 

[bruceb58]

Re: strange electrical issues lowrance is reading 6volts

You have a resistive connection either on the ground or power side that is causing a voltage drop when your unit puts a load on the circuit.

To figure out which side it is on do the following. With a meter and a long jumper lead, measure the voltage from the positive wire feeding your unit to the battery positive post. Should read zero. Do the same on the negative side feeding the unit to the negative post on the battery. Should also read zero. If you have a 6 volt drop, you will measure it with the sum of the previous two measurements.

 

[Bustedknuckle84]

Re: strange electrical issues lowrance is reading 6volts

Fish Finders are Locators. Regardless what the manual says, fish finders do not find fish. They identify the presense of fish when they fall under the sonar beam. Just because you installed a NEW battery does not mean it is good, nor does it mean it was fully charged. Since the stereo is doing the same thing as the locator, you have power distribution problem. Does the charging system on the outboard work? What terminal on the ignition switch do you have the locator and the stereo connected to? If it is not on the "A" (accessory) terminal it is no wonder things aren't working.

The key ignition switch isnt plugged to any of my electronics. However I have a power wire going to a simple distribution block with fuses. I tried connecting to a power wire not on the distribution box and still same problem. The batteries are strong enough to turn the motor over to stop, not sure if that makes a difference. but if I had the problem before installing the new battery and after new battery so I don't think its the culprit. Not sure if charging system works because i just bought the boat, is there a easy test?

 

[Bustedknuckle84]

Re: strange electrical issues lowrance is reading 6volts

You have a resistive connection either on the ground or power side that is causing a voltage drop when your unit puts a load on the circuit.

To figure out which side it is on do the following. With a meter and a long jumper lead, measure the voltage from the positive wire feeding your unit to the battery positive post. Should read zero. Do the same on the negative side feeding the unit to the negative post on the battery. Should also read zero. If you have a 6 volt drop, you will measure it with the sum of the previous two measurements.

whats a resistive connection? is there something specific I should be looking for?

 

[Bustedknuckle84]

Re: strange electrical issues lowrance is reading 6volts

thanks for the infor guys, I will be working on this tomm, Ill use the above info to help me. I'm starting another thread with a separate question about identifying a component of the electrical wiring. Please chime in...

 

[bruceb58]

Re: strange electrical issues lowrance is reading 6volts

whats a resistive connection? is there something specific I should be looking for?

Could be a loose ground wire, loose positive feed at your fuse panel. The voltage check will at least split the problem in half so you know which side has the problem.

 

[Bustedknuckle84]

Re: strange electrical issues lowrance is reading 6volts

sounds like a plan ill repost tomm with my findings

 

[NMShooter]

Re: strange electrical issues lowrance is reading 6volts

Bruce nailed it.

You have a bad connection somewhere. If you have a loose connection somewhere inline, or corrosion, it will cause your electrical device to see a lowered voltage. Here's the odd part... you only see the lowred voltage when you turn it on.

Sort of like a kink in a hose. You can still get full pressure at the end of the hose with a kink in it, but only if you are not drawing water. As soon as you start to let water flow, the pressure goes down due to the kink.

This can also be caused if you use too small of a gauge of wire and have a long run.

Good luck.

P.S. This very problem causes houses to catch fire too. All of your electrical outlets on a circuit are daisy chained together. If #1 has a bad connection, then everything down line suffers. Plug in lots of stuff, and that bad connection on #1 starts to get really hot and can overheat. You can check your outlets at home with a voltmeter attached to a plug, but you also need to plug in something hefty like an electric skillet on the same outlet while you are measuring the voltage. You don't ever want to see more than a 5% drop at the farthest receptacle... something on the order of 114V or less is cause for investigation.

 

[Bustedknuckle84]

Re: strange electrical issues lowrance is reading 6volts

Thanks for the info everyone. Problem solved. I had what I thought was a good ground to the distribution box. Hooked up a nice solid ground and viola!