electrical problems SN 1987

A better description of your problem would be helpful.

What makes you think it is an electrical problem?

Pull down = voltage drop?

Voltage readings at the alt and batt both when running normally and when you're experiencing the issue would be a good start.

10v at the dash with the lights on is not atypical. The kind of voltage drop due to marginally sized wires to the dash, compounded now by age and corrosion on the wiring, connectors and breakers will exacerbate it.

Other than the voltage drop you're seeing, are you experiencing driving or starting problems? I can't tell from your description.

In that case you can learn to live with it until it gets worse and starts causing functional problems... Or you can adress it in a few ways:

- clean up dash wiring- clean/repair/replace dirty or corroded wires and connections. Consider adding dedicated ground, ign and batt buses and eliminating the daisy chained connections.

-replace circuit breakers as necessary (ign being the most obvious) as they can degrade internally and contribute to voltage loss

-run additional (larger?) 12v, gnd and ign wires from the engine to the dash to eliminate the effect of the undersized/degraded harness.

chuck kemp wrote: After running the boat awhile engine will not turn over. Battery will build up after a 10 min break and boat starts fine.

So the engine doesn't die but when shut off won't immediately start back up?

I feel like I need a translator here

"Drag after shut off"?

I'm thinking maybe, the boat is charging fine, but the heat buildup of the running engine is increasing the resistance, therefore showing diminished numbers on the Voltmeter after warmup.

Check the timing. It may cause the slow crank. As Tim mentioned, get the VOM out and check voltages and resistance's BEFORE buying parts!

BTW, hopefully you didn't purchase a deep cycle battery!