Oil pressure guage pinned

[BIGBlack87K5]

My oil pressure gauge is pinned all the way up but the truck is running the same is it the oil pressure sending unit?

 

[4X4HIGH]

It is probably the sending unit. I'm going to assume that it's on an 87 K5 judging by your user name? If so there were two different sending units used on the TBI trucks, one is a single wire and the other is a 3 wire. The 3 wire is a dual purpose sender which controlled the fuel pump relay backup and also the oil pressure gauge. Just make sure you know which your is before you go to buy one.

 

[BIGBlack87K5]

Thanks and yes it is an 87 350 tbi k5

 

[Fordum]

4X4, does the sending unit on that one ground the gauge to make it go up? I'm thinking a shorted sending wire to ground. Might pay to check that first.

J

 

[4X4HIGH]

4X4, does the sending unit on that one ground the gauge to make it go up? I'm thinking a shorted sending wire to ground. Might pay to check that first.

J

I'm not certain but i do think so. I know if you wrap the fitting with teflon tape the gauge won't work properly so that makes me inclined to say the sender DOES require a good ground.

 

[corelokt]

Yes, they work by allowing the ground to have less resistance as the pressure goes up. Water temp units are the same way. A shorted wire is the first thing to check.
BTW, if you ever have to work on your wiper motor, it is fed live power, and controlled by wick terminal is grounded. Spent a lot of time on a CK plow truck I rewired figuring that out.

 

[BIGBlack87K5]

Thanks guys ill check that out

 

[bhays]

I have the same problem and I replaced the sending unit and it did not fix the problem. I would check the ground...