Westerbeke 4.5 KW BCGTC generator blows 8 amp fuse

John, great post from 2006. Thanks for sharing the link!
 
vanman59,

Jumpered the two wires and the fuse still does not blow which is good. I would have thought that jumping the wires would have allowed the generator to run without holding the start switch, but it didn't. Thoughts?
 
I will pull the schematic on your generator and see whats going on.

John
 
Last edited:
https://www.westerbeke.com/operator's manual/42832_bcgtc_gas_operat_man.pdf
Page 20

T3 Circuit has:

-Exhaust Temp Normally closed
-Oil Pressure Switch open on start then closed
-Water Temp Switch normally closed.

So the Shut Down board is looking for a closed circuit from T3. Jumping the two leads on the switch should have solved the problem if it was the oil switch. Before I speculate any further....if you hook the leads back up to the oil pressure switch ....the 8 amp fuse blows?
 
Sounds like you may have more than one problem, if the fuse doesn't blow with the oil pressure switch out of circuit but does when the oil pressure switch is in circuit I would replace it. If you still have to hold the run switch you still have another problem. Are you using a remote panel or the switches on the generator? The reason I am asking is that it sounds like you need to check for 12 volts at input of the water temp., exhaust temp. and oil press switches. I hope I am helping my gen is old school and has no electronic control, all manual switches, relays and mechanical governor.
 
If you have bypassed the oil pressure switch with a jumper, pull the jumper wire off the oil pressure switch wires and check for 12 vdc on one of the wires. If you don't have 12vdc on one of the wires you have lost the voltage that allows the generator to run without the "on switch" being held. Check for voltage at both sides of the water temp switch and exhaust temp switch. My guess is one of those switches is open or a wire between them is.

12 vdc comes from the 8 amp fuse then goes to the On Switch, Over Speed Circuit and the Engine Protection Circuit (Water Temp Sw. to Exhaust Temp Sw., to Oil Press Sw.). From the output side of the Oil Press Sw. 12vdc goes to the Carb Solenoid, Fuel Pump and Ballast Resistor (this is what allows the generator to run, fuel pump pressurized, carb solenoid energized and 12vdc to ballast resistor to + side of coil (during start the relay K1 bypasses the ballast resistor to supply 12vdc directly to coil to give the coil a little more juice because the starter is drawing current during the start cycle). When the "On Switch" is held 12vdc goes directly to the Carb Solenoid, Fuel Pump and Ballast Resistor because it bypasses the Engine Protection Circuit this is how the generator can run until the oil pressure builds up enough to close the oil pressure switch and you release the On Switch.
 
So, I realized at some point the remote station run switch would need to be on for it to run without holding the start switch at the generator and it did. So, with the switch disconnected and the wires jumpered she runs. Problem solved once I install the new switch. Thanks for all the information that helped me learn a lot about my Gennie!
 
As a more complete update, I have now correctly identified this as the Oil Temperature Switch, part number 043242. Hope this and this thread helps another at some point. Thanks!
 
I'm sure it will all of us have issues like these from time to time. Even non members find the site and use it to help get things fixed
 
Had the same blown fuse issue with my Westerbeke. Like above, mine was a faulty oil temp switch. I was able to verify the switch was faulty by placing in hot water, greater than 120f, and checking continuity across the terminals. At 120f you should see continuity, if not, the switch is bad.
 
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