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Topic: Oil pressure switch woes  (Read 212 times) previous topic - next topic

Oil pressure switch woes

I replaced the oil pressure switch on my propane onan generator. The switch I used has mostly the same specs, the same low pressure value and a slightly higher high pressure value. There is an appropriate amount of oil in it, but it won't let the generator turn on. When I bypass it (see attached picture) it works just fine. Are there any common mistakes one might make when installing a new one?

1987 Grand Villa ORED
2001 U320 4010

Not all that wander are lost... but I often am.

Re: Oil pressure switch woes

Reply #1 –
Did the old one fail or was it just leaking?
1999 40 ft. U-320 wtfe build 5563 Chuck & Lynda's "Rollin' Inn"  2030 watts solar
prev. mh's 71 GMC 5 yrs. 73 Pace Setter 1 yr. 78 Vogue 5 yrs 81 FTX 40ft all electric 18 yrs. 1996 Monaco Signature 3 yrs.
2014 Grand Cherokee Overland
Dream as if you will live forever. Live as if you will die today.  James Dean

Re: Oil pressure switch woes

Reply #2 –
Quote from: craneman –
Did the old one fail or was it just leaking?
I Was having issues with keeping the generator running while driving down the road (but it worked fine when stationary) so it was something I replaced in an attempt to resolve that issue
1987 Grand Villa ORED
2001 U320 4010

Not all that wander are lost... but I often am.

Re: Oil pressure switch woes

Reply #3 –
Is the new switch normally open? I don't understand the same low and high values you posted. It should only have a low pressure open circuit. There is only one wire and breaking the circuit shuts down the engine.
1999 40 ft. U-320 wtfe build 5563 Chuck & Lynda's "Rollin' Inn"  2030 watts solar
prev. mh's 71 GMC 5 yrs. 73 Pace Setter 1 yr. 78 Vogue 5 yrs 81 FTX 40ft all electric 18 yrs. 1996 Monaco Signature 3 yrs.
2014 Grand Cherokee Overland
Dream as if you will live forever. Live as if you will die today.  James Dean

Re: Oil pressure switch woes

Reply #4 –
Quote from: craneman –
Is the new switch normally open? I don't understand the same low and high values you posted. It should only have a low pressure open circuit. There is only one wire and breaking the circuit shuts down the engine.
You know I don't know, I replaced it a long time ago but didn't have any propane to test until recently. Should t be NO or nc?
1987 Grand Villa ORED
2001 U320 4010

Not all that wander are lost... but I often am.

Re: Oil pressure switch woes

Reply #5 –
So after MUCH sleuthing, I was able to determine the old part# for the pressure switch on these coaches is  309-0237 NOS. I just ordered one to the tune of about $50. This is for a 6.5 NH-3cr/16004p gen set from the late 80's

I have not been able to find a more modern part # for a replacement but here are the specs for it:  pressure sending switch 8-10psi 1/8"-27 threads NOS

Posting this for the next guy and will follow-up to confirm it works
1987 Grand Villa ORED
2001 U320 4010

Not all that wander are lost... but I often am.