Electric Short - Gauge Problems?

[focker1636]

Over the past month I've had intermittent warning indicators in boat and finally traced down the cause to an electrical issue. When I turn on the nav lights my temperature gauge immediately climbs 70-150 degrees. Turn the nav lights off and the temp gauge returns to normal.

So, I'm assuming the obvious place to start is the console. I'm not totally knowledgable in the area of tracing electrical shorts, but I'm guessing the first step is to look for frayed wires.

Any other tips from you boat gurus out there???

 

[Silvertip]

Re: Electric Short - Gauge Problems?

Frayed wires is very unlikely. Wires whose terminals have twisted on the switch or gauge terminals thus touching things they are not supposed to is more likely the issue. Since you said the gauge "climbs" 70 - 150 degrees, that would mean it is nearly pegged on the high side correct? What causes that is the send terminal (the "S" terminal) on the guage has been put to ground so look for a link between the "S" terminal and the Nav light switch. They are totally unrelated with one very important exception. That being the internal light on the gauges. When you turn the NAV lights on, that also turns the lights on for all of the gauges. If there is a loose connection, dangling wire or a wire that has moved around on its terminal, that could cause the issue. So start at the back of the TEMP gauge. Make sure none of the terminals are touching each other. Pay attention to the light "L" terminal and follow it from one gauge to the next, then the next, etc until you get to the NAV switch. The problem is very likely somewhere in that lighting system.

 

[focker1636]

Re: Electric Short - Gauge Problems?

Thanks, I'll give that shot.

 

[focker1636]

Re: Electric Short - Gauge Problems?

Well, I removed the gauge panel and just my luck it's one big circuit board with all of the gauges on a single panel much like an encased automobile dash panel.:-(

Is it most likely the short is in the circuit bord? Looked at the wiring going into the two harness plugs going into the board and that seems OK.

 

[seabob4]

Re: Electric Short - Gauge Problems?

You definitely have a ground issue. Keep in mind for future trouble shooting, about 97% of all 12VDC electrical issues are due to a bad ground...

 

[focker1636]

Re: Electric Short - Gauge Problems?

You definitely have a ground issue. Keep in mind for future trouble shooting, about 97% of all 12VDC electrical issues are due to a bad ground...

Would the ground issue most likely be in the actual cluster or in the wiring coming out of the harness? What should I check next?

 

[Silvertip]

Re: Electric Short - Gauge Problems?

You are probably at the point where unless you have a multi-tester and know how to use it you've done as much as you can. That said -- verify that the ground wire going into the panel is actually at ground -- meaning it has continuity all the way back to the battery. Then verify you have 12 volts INTO the panel with the key on.