oil pressure gauge

[89chevsj]

so my oil pressure gauge reads the max all the time.on start up it will jump up a little like it should but it never drops to a normal pressure. not even when the truck is not running. im thinkin bad sending unit? what do you think? its an 89 chevy 350

[kevhill85]

Sound like you need a new sending units
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[89chevsj]

ok thats what i thought. but just in case heres a little i just thought of. the gauge use to read normal then it started fluxuating up to the max back down to normal and then while driving it short up and never went back down.

[89chevsj]

and if anyone has the time to run me through finding/replacing the oil pressure sending unit, I'd be much obliged if they would do so.

[ChevLoRay]

Could be the sending unit....could be the wire from the sending unit has a break in the insulation and is shorting out. Some guages read full-scale when shorted (electrically, as designed) while other guages read "0" when shorted....meaning the sending unit is passing all the current that it can.

If the wire has a break in the insulation, and it is shorting to ground, then the guage will react like the sending unit is doing its job normally.

By the same token, you should be sure your grounds are all good....frame to cab, etc. If you are having any other electrical issues, bad lighting, etc., that could be a problem area. You do live where it snows and roads are treated. Rust is a way of life....

[89chevsj]

the truck also has 40k on a complete restore. but it wasn't done by me so I'm not sure about the shorting, but another thing thats got me confused is the temp gauge went to 0 at about the same time as the oil pressure went out. thoughts? where are the common places for the wires to rub the insulation off, firewall?
edit: the gauge goes up on initial start up and back down to 60. i can tell it moves. still sound likeapossible short.

[ChevLoRay]

If you have issues with two guages on the same panel, the chances are good that it's a problem with your panel, like a bad ground...i.e., when you hear hoofbeats, don't go looking for a zebra.

[Dezdad1]

Originally Posted by ChevLoRay

If you have issues with two guages on the same panel, the chances are good that it's a problem with your panel, like a bad ground...i.e., when you hear hoofbeats, don't go looking for a zebra.

My gauges do the same thing when i turn the signals on they go up and down ??? 88 . 1500 350...??????????

[ChevLoRay]

Sounds like you also may have a grounding issue. Electricity seeks the path of least resistance...but it will find one if possible. Sounds like you're gonna have to do some up close and personal scrutinizing of the back side of your panel and inspect the connections and the grounding. I understand there should be a ground connection towards the right end of the panel, but don't take me to court if that's not where it is.

[89chevsj]

ok Mr. Zebras haha. my voltmeter didnt work for the longest time. bought a new cluster and it works fine now. but the other two still dont. where should i look for a grounding issue?
sorry shoulda read the last post.

[Dezdad1]

Originally Posted by ChevLoRay

Sounds like you also may have a grounding issue. Electricity seeks the path of least resistance...but it will find one if possible. Sounds like you're gonna have to do some up close and personal scrutinizing of the back side of your panel and inspect the connections and the grounding. I understand there should be a ground connection towards the right end of the panel, but don't take me to court if that's not where it is.

Thanks i will give it a try ...I wanted to put in a cluster with a tach so this is a good time for that....