Dead Boat

[dpoff]

Got my boat back after engine reinstall... Took the boat out and fuel gauge is pegged past the full mark. I knew that the sending unit needing replacing because of a small amount of fuel leakage past the positive connection when the tank was topped off. I already had a spare one to change out and I did so.
Well, no change ,so I started checking wires for shorts etc.. I found a broken/corroded/(burnt) ground wire from the sending unit and hooked up a jumper between the break, no difference. Then I found that they had hooked up a dedicated ground from my bilge pump to the positive terminal on the battery!
OK, Bad ground for the gauge i figured, switched to correct polarity and thought all would be OK.
Well boat power went dead. No Power on dash, No igintion, Nothing. I checked the circuit breaker on the engine and the fuses behind the dash and all looks good. Im stumped right now.
Any thoughts?
I`ll be back at it tomorrow, starting from the battery to the battery selector switch and on up.
BTW this is a 1974 165 hp Mercruiser set up, Seabird boat

 

[Bifflefan]

Re: Dead Boat

I`ll be back at it tomorrow, starting from the battery to the battery selector switch and on up.

Sound like a good place to start.
Check the batt and charge as nessarry then go from there. This could be a long process but well worth the time. Repair anything that is found along the way. Check your progress as you go along to see if it comes back to life.

Finish the job by continuing though the entire wiring harness even after it runs, just so you dont have a problem later.

BTW a pegged fuel gauge is either a short or open. Depends on the wiring.

Good luck and let us know what you find.

 

[dpoff]

Re: Dead Boat

Fixed!
I started out with the voltmeter and as I was tracing wires I found a black wire with a ring terminal not connected to anything that was hidden behind the starter.Turned out that was the ground was for the dash power! I slid it onto the engine ground post and everything worked fine. It appears all or the dash components were using the fuel sender ground until it burnt. Only took 15 minutes to get er done. What a relief to find the easy fix.
Now I can go fishing tomorrow!

 

[david_r]

Re: Dead Boat

i would add a few grounds to make up for the shortfall........ you dont want wires burning in half on top of your fuel tank!!