Oil pressure gauge

[fyrfightr]

93 4.3L with Gen II drive. When I turn the ignition switch on the oil pressure gauge pegs at 80lbs. Stays there when engine is running. If I unhook wire at sending unit, gauge reads zero. Replaced sending unit today. Getting same symptoms.

Tried testing the new sending unit today with VOM. did not get change like I thought I would.

I assume I have oil pressure as the idiot buzzer goes quits when I start the engine.

'
I have been having this issue since getting this boat 3 years ago....

 

[tupperj]

Re: Oil pressure gauge

Fyrfightr,

Don't know of you have the manual or not, but the troubleshooting section calls for a reading of about 240 ohms across the sender with the engine off, and about 100 ohms at 40 psi.
Pegged meter should mean a short to ground.

Is it possible you have a dual station sender installed? Manual says it should have 353M stamped on it. Those senders show a much lower resistance for a given pressure evidently.

I'd be looking to T in a standard gauge just to be sure you know what the engine in doing.

Good luck!
Paul

Edit: this info is for a 3.0 engine, don't know if it's applicable to your 4.3. Need to pay more attention!

 

[fyrfightr]

Re: Oil pressure gauge

Will have to go take an ohm reading on the old sending unit and see what it says...

 

[fyrfightr]

Re: Oil pressure gauge

I get a readings of 380 one direction and 500 the other direction using a digital ohm meter.