BJ74 - Oil pressure gauge not working

[nickw]

So about 2 days ago my oil pressure gauge starts acting funny.
I happened all of a sudden. I shut my truck off, and the next time I started it, it went funny. It went straight to about 95% max on the gauge. Way, way above normal. I drove it the 1km home, because I new the oil pressure could not be that high. It also went to that high when the engine was not running. If the key was in, it went up. So it had no relation to the engine running or not.

Next day it did the same. I changed the oil as good measure just to rule out a plugged filter or something. Anyways, I keep driving it to see what it does. Last night I had about 45 minutes of running around to do. About 20 min in, its starts to slowly come down. Once it got to the half way mark it just shut off completely.

Now it will not come back on no matter what.
Does any one have any ideas?
Anyone know where to start?
Common problem perhaps?

I hate electrical issues.
So any help would be appreciated.

Cheers.
Nick

 

[Kaney]

yea this would be interesting, my 78 series has just done the same thing. i have been told its the sender, but then another guy said its the gauge itself. so i will keep and eye on this with interest

 

[Mudkiwi]

Try taking the wire off the sender unit on the side of the block and earthing it out, if the gauge goes up then its a faulty sender unit.
If it doesnt then its the gauge.

 

[Gold Boy]

check the ground wire.

 

[wesintl]

mine did the same wheelin in moab, bout had a heart attack thinking I had no oil pressure. It acted funny the rest of the week. Sometimes worked, sometimes didn't.

When I got home I pulled the sender. cleaned the contacts and blew out the where the oil goes. It's been fine ever since.

A new sender isn't all that much from the dealer either, assuming the 3bt is the same as a 3b