[Uberbigun]

Cross-posted from P30 forum:

I have a 1976 P30 with a non-functioning mast head light. After five trips up the mast, I have determined that

a) The mast head light works fine. - I tested it with my VHF wires inside the cabin
b) With the mast head light removed, I get 14+ volts from the black and white wires.
c) Holding the negative lead from my multimeter to the shroud, I also get 14+V
d) Whenever I put a load at the top of the mast, (i.e. light bulb) the voltage drops to zero.

I suspect the problem is in the mast step somewhere, but can't figure out where the wires enter the mast from. I suspect they go from the port side, up through the headliner, and then under the compression post. I also suspect that the wiring problem is at the base of the mast. Does anyone have any troubleshooting suggestions? This weekend I am planning on using a wiring toner to trace the line and rule out any issue inside the boat.

Frustrated in Deale, MD -

Scott