Electrical Problems

[Tim Twigg-Smith]

My boat has twin 1997 vintage cummins 350C engines with just under 3000 hrs….all stock Cummins marine Panels and harnesses.. I guess the marine age/low maintenance/no maintenance is catching up as I went to start the port motor – turned key , nothing.. There is 12.5 volts where the red wire attaches to the key switch. .the Purple wires have no juice.. If I remove the purple wires from the other terminal on the key switch, than there is 12.5 volts at the other terminal when the key is on.. so there must be a ground problem in the purple circuit?? if I tie open the fuel solenoid and jump from the keyswitch to the yellow red stripe wire , the motor starts and runs fine.. the surprising thing to me is that if I touch a 12v + lead from a different battery to the red wire terminal, the panel works as does the upper panel.. looking at the diagram, the purple flows to the upper panel and then to the fuel solenoid and the ‘replaceable diodes’… Can anyone give me an idea of where to start looking/replacing..? Question 2: Looking at the diagram, what are the ‘replaceable diodes’? where are they?

Thank you, Tim

Topic

[Tim Twigg-Smith]

Time to get to work

Ok, you are right. Its time to clean it all up.. Hopefully nothing is broken and it just needs a good go over.. I’m guessing the replaceable diodes are in the alternator, right? do those ever give troubles? I’m looking for issues in the purple circuit especially as I go..

[Tony Athens]

Electrical Contact Issues

Tim,

Come on — you already know the answer——You have wires &/or connections that are well over a decade old with dry white stuff on them and “loose or worse”, etc…………..

It means this: take apart EVERY connection, clean with WD-40 and a tooth brush, re-assemble using either white lithium grease or Corrosion X or or a combo of them (Our way) ..

Find the circuit breaker on top of your engine and replace it and redo the connections.. Spend day doing this and you issue will be solved..

Don’t forget the main battery cables —all those connections + & – all the way to the battery.

Tony..

[Author]

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