Who'da thought of that
 

I have been having problems with the instrumentation on my Tolman. Of
course since it is home built all the instruments were installed by
me. Everything would work very well in my driveway at home but on the
water the depthsounder and VHF dont work. Of course I have backup
handheld VHF but no depthsounder and this has limited where I went.
I checked my wiring, used VOM to check continuity in the wires.
Finally checked the voltage betwen the positive buss and ground Buss.
At no load, 12.5 volts, no problem. Just happed to turn on the VHF
witht eh VOM connected and keyed the mike and the voltage dropped to 6
V, HUH?
Only way that could happ is resistance somehwere, so I checked my
connections, all ok. Checked everything else and finally out of
frustration checked my 8 guage ground wire, 3 OHMS, WTF? This is
expensive tinned all the way through stuff and only 3' long. Sure
enough, it seems to have an internal break, or near break. I had more
of the stuff remaining on the spool so replaced that piece and
everything SEEMS to work in the driveway once again................