Power to light in head of Cat 34 MKII

[eisjeff]

I have lost 12-volt power to the over head light in the head. Unfortunately the wiring appears to have been done before the deck was put on the boat and I can't trace it nor can I find a path to run a new wire to the light.

Look for ideas besides replacing the light with a battery powered one.

Thanks

[Jim Hardesty]

I can't trace it nor can I find a path to run a new wire to the light.

To answer your question with any specifics need more information.  Year and model would be a good start.  It's been my experience that the wire is rarely the problem. Chances are it's a bad connection or fixture.  The switches on the fixtures often are a problem.  A good multimeter, one with a audible continuity, is helpful. Of course know the basics of using it.
Happy hunting,
Jim

[JeffG]

I've always been curious how the wiring is routed.  Is it embedded in the cabin top, or is there some sort of conduit or channel?  I wonder if a tone generator circuit tracer tool could trace the cable routing to help find an access point.  https://www.amazon.ca/s?k=tone+generator+tracer

On the chance that its just a bad connection somewhere: The wiring diagram shows that the head light positive wire is connected to a main wire that then goes to the chart table light and then the port side salon light before going to the electrical panel.  I assume those other two lights are working?    The connection at the chart table light might be a good place to check continuity to since its easily accessible.  Check for continuity from the head light positive wire with the breaker off.

It looks like the negative wire goes directly to the DC negative buss bar behind the electric panel.  Another continuity test you can try.

/Jeff

[Ron Hill]

eis : Check the bulb and then check the fixture with a multimeter. Also check to make sure that there is power coming to the fixture- that head light is on the cabin light circuit.

If the checks fail and there is NO power to that light fixture - that light fixture is right next to the engine bulkhead so on the other side is a source of all kinds of 12V DC power!!
I'd recommend a new positive wire from the starter solenoid and a new negative wire from the engine block!! 

A few thoughts

[Jim Hardesty]

FWIW.  The second season I had Shamrock the GFCI started to trip occasionally.  When I troubleshooted I found a bad, poorly made, crimp to the outlet.  The wire easily pulled from the connector.  Easy enough to fix.  Then I thought if one connection was bad, were others also bad?  So, one rainy day I gave all the connector/wire a firm pull and a good look.  Found a good number of them pulled out or were loose. That was AC and DC, receptacles, busses and breakers. Catalina factory must have had a bad crimping tool.
So, if your hull number is close to Shamrock,1570, it may be worth checking the connections.
Jim