Westerbeke 8.0 BTDA kicking my arse

This is the wiring diagram from my 8.0 BTDA manual that I am using for debug.

 

Fixed it! Error by yours truly. This generator has two oil switches. One for low pressure shutdown and an auxiliary for Sea Ray system monitor alarm. I had analyzed the auxiliary had gone bad, bought its part number and replaced it. But noooo! After tracing wire colors it was the shutdown switch that went bad and I put an aux switch part number in its spot. Jumpered it and runs on and on normally now. The two switches are different so gotta go buy the right one. Now he has a spare aux oil switch. Ha!

Also I discovered the power runs serially through both the on generator stop switch and the remote panel start/run switch. With the remote panel switch off, that creates an open circuit. You have to put it in the run position for the generator to continue running when started from the on generator switches.

 

The one with the thicker white wire going to it is the shutdown sensor. You’ll probably need to scrap the red paint away from the wire to see it. The system monitor switch is a smaller black wire with white stripe.

 

And the beat goes on...

I put in the correct oil shutdown switch. That fixed that. After researching it’s normally closed above 10 psi and opens below that. The Sea Ray auxiliary switch is the opposite. Normally open and closes at low pressure. So that explains that.

Oil gauge has never worked since he bought the boat. Needle just hung limp straight down. Replaced oil sender and that fixed that.

Temp gauge is pegged to right. Replaced temp sender and no change. So that leads to the remaining problem. All three gauges peg to right when engine is running as if all senders are shorted to ground. When shut off the oil and voltage gauges return to normal off position. But temp gauge stays pegged. And here is the interesting part. With ground cable of generator start battery disconnected, there is still power to the control panel to activate gauges and relays. Seems like there is a short to the boat ground system somewhere. I have some research to do to attack this one.

Two pictures attached are the gauges with generator running. And with generator in ON position but not started.

By the way if you need to replace temp sender, remove belt, alternator and alternator tension bracket. So much easier to get tools and hand back there that way.

 

I went back to the boat today and I tried every possible combination of disconnecting wires at the gauges. Never got rid of the problem. So I disconnected the ground wire from the gauges and ran a wire direct from the battery (-) to the ground on the gauges. Problem still there. Could it be the battery? It has a real hard time starting the generator now as well. Each gauge reads 12.4v at its power posts with a multimeter. I guess it’s possible all three gauges are bad. Multimeter reads 12.4v at voltmeter while the voltmeter needle is pegged.