FINDING A GROUND WIRE

[Tom7227]

As I try to fix my HDS 5 I am having trouble finding a ground wire.  The boat is a Crestliner pontoon and there is a fuse block built into the console.  There is a fuse marked for the depth finder and so getting to the hot wire isn't going to be a problem.  There are 10-12 fuse slots in the block.  There are two tabs coming out of the short end of the block and they don't line up with any fuses.  Is it likely that they are part of a grounding buss for the system?  The wires that were left behind by the thief have two female ends on them and the leads are fairly short and obviously were wired close together which would make it seem as if the tab I am looking it is the ground.  Thing is that I hooked a 12v test light to the tab and touched the probe to the tab for the hot wire on the depth finder and the light didn't light.  Power was on and the fuse was good.  It is about impossible to see into the area where the fuse block is to get a good idea of the layout. 

[delcecchi]

That is something that either the local crestliner dealer or support at the crestliner pontoon factory should be able to help with.  The guys that rig them must know the answer. 

As for the test light, I might try a multi meter, or one of those inspection fiber optic deals would help to see it.  You could rent, borrow, or if all else fails, buy one at harbor freight.  Or at the local big box store and return it, if that works for you.

[boatfixer]

Hook the ground end of the test light to a known hot wire the use the probe to find a good ground.

[marine_man]

Using a test light is a good idea.. normally, near the fuse block there's a corresponding ground block attached to it or very near it.

No idea what the dash looks like, but if the gauges are mounted to a common panel you could pull the instrument panel to get a better look inside.

Do the switches on the pontoon have a light on them that lights up when it's on?  There is always a ground on those that you could piggy back off of if nothing else.

marine_man

[Tom7227]

Boatfixer's idea worked perfectly.  It seemed sort of backwards to use the test probe from hot to ground but it was pretty straightforward once I got set up.  The tab I originally tried actually was a positive tab but there was a negative tab on the other end of the fuse block.

Thanks for the help.

Tom