Westerbeke genset 8.0 btd won’t stay running

[TRG]

They are two different switches. One is normally open, the other is normally closed. In that thread I referenced, a few posts back from the reference post, you can read where I installed the wrong one.

Also, later in that same thread you can read where Tom (ttmott) helped me figure out that all the switches were good, but the preheat solenoid was blowing the 8 amp fuse. I worked around that by disconnecting the preheat solenoid since where I boat the generator starts right up without the glow plugs heating up.

I have been looking at the wiring previously and today and I don’t know if previous owner may have incorrectly hooked wires up to the generator when working on it? When looking at the wire schematic I found wires not correctly hooked up to the 2 oil pressure switches so I am not sure what switch is the pressure switch and which one is the alarm switch. Also when looking in the control box the wires going to the K1 and K2 blocks don’t match the schematic. Also not positive which block is the K1 and which is the K2. I am guessing the top block is the K2 and bottom is K1 based on the wires that are plugged into them but their positions don’t match the positions on the schematic. Not sure if their positions matter or if they just need to be plugged into the correct block? Here is the schematic I have and a couple pics. https://www.manualslib.com/manual/681487/Westerbeke-8-0kw-60hz.html?page=31

I also don’t have the issue of blowing the 8amp fuse any longer after adjusting the oil pressure switch wires but still dies unless I have preheat switch held down. I also rechecked the diode I put in and it is showing .65 one direction and OL with polarity reversed.

 

[ZZ13]

I have been looking at the wiring previously and today and I don’t know if previous owner may have incorrectly hooked wires up to the generator when working on it? When looking at the wire schematic I found wires not correctly hooked up to the 2 oil pressure switches so I am not sure what switch is the pressure switch and which one is the alarm switch. Also when looking in the control box the wires going to the K1 and K2 blocks don’t match the schematic. Also not positive which block is the K1 and which is the K2. I am guessing the top block is the K2 and bottom is K1 based on the wires that are plugged into them but their positions don’t match the positions on the schematic. Not sure if their positions matter or if they just need to be plugged into the correct block? Here is the schematic I have and a couple pics. https://www.manualslib.com/manual/681487/Westerbeke-8-0kw-60hz.html?page=31

I also don’t have the issue of blowing the 8amp fuse any longer after adjusting the oil pressure switch wires but still dies unless I have preheat switch held down. I also rechecked the diode I put in and it is showing .65 one direction and OL with polarity reversed.

My factory wiring doesn’t exactly match the schematic. I’d go with what’s there now. The switch with the two thinner black wires should be the system monitor switch. The thicker red wire one should be the safety shutdown switch. Easy to figure out. If your system monitor is alarming when you start generator, just unplug one of the black wires and it should no longer alarm if that is the system monitor switch. Then jumper the wires to the other switch to bypass the oil shutdown switch and see if it keeps running.

Looks like you said you swapped the wires to the two oil switches. It’s probable it was right to begin with and now you have the shutdown circuitry connected to the wrong switch. Since it’s the opposite of the shutdown switch, when pressure builds it will open. Then when you let off preheat you now have an open circuit at good oil pressure. I’d swap them back and then do what I posted above. But that’s just me.

 

[TRG]

My factory wiring doesn’t exactly match the schematic. I’d go with what’s there now. The switch with the two thinner black wires should be the system monitor switch. The thicker red wire one should be the safety shutdown switch. Easy to figure out. If your system monitor is alarming when you start generator, just unplug one of the black wires and it should no longer alarm if that is the system monitor switch. Then jumper the wires to the other switch to bypass the oil shutdown switch and see if it keeps running.

Looks like you said you swapped the wires to the two oil switches. It’s probable it was right to begin with and now you have the shutdown circuitry connected to the wrong switch. Since it’s the opposite of the shutdown switch, when pressure builds it will open. Then when you let off preheat you now have an open circuit at good oil pressure. I’d swap them back and then do what I posted above. But that’s just me.

You are correct. Factory wiring does not necessarily match. I was able to get the issues figured out and generator now runs correctly. Thank you all for all the pointers and help to this newbie.

findings: diode was bad and replaced, wiring on oil switch and aux oil switch was set incorrectly to terminals. PO had 1 wire from each switch crossed then once I traced them and verified they were crosssd I attached the aux oil switch wires to the oil switch and vise versa. Figured this out once I switched them and alarm started working in the electrical panel cabinet. Then found oil switch was bad and replaced.

thanks again to all, great forum. I hope to pay it forward once I learn my boat more.

 

[dtfeld]

This is one of the more complicated issues I've run across and if you solved it your good for about anything else!

 

[ZZ13]

Well done!

I’ve been through several of these debugs and with Dave (dtfeld) and Tom’s (ttmott) help pretty much have the circuitry reverse engineered. Here’s a couple things I figured out that weren’t discussed in this thread:

You can test the diode without removing it. One end of it is connected to the preheat solenoid. The other end of it is connected to the oil pressure shutdown switch. With the generator off remove the purple/white wire from the preheat solenoid and the red wire (the other wire is red/purple) from the oil shutdown switch. Those are your two ends of the diode. The preheat switch and the start switch and the k2 run relay in the open position isolate the rest of the circuitry from the diode.

The diode serves two purposes. With preheat switch on it is the path for current to bypass the shut down switches and energize the k2 run relay. With generator running and preheat switch off it blocks current from continually energizing the preheat solenoid.

 

[TRG]

Good note. The diode is a pain to get off and back on with all the other wires on the terminals. Only bad thing is that it seems from most of the other generator won’t run posts the diode is usually bad so you still have to remove and reinstall.