Oil Pressure Gauge and Sending Unit Troubleshoot And Repair GM Trucks

Just a simple walk along video tutorial showing how to troubleshoot, test, diagnose and replace the factory oil sending unit for your squarebody Chevy and GMC truck.
This is for 1978-1987 trucks and GM cars using a factory oil pressure gauge.

[@melvis2017]

Thanks for the update and the way you explain things thanks once again for the efforts and for sharing this with us appreciation. From tomorrow am gona try with the same way you did om my old jeep from 1948🇩🇰🙏👍

[@American-OutdoorsNet]

Thanks for tuning in!

[@mibars]

Late square bodies (last facelift) use different style oil pressure sending unit, which combine function of a sending unit with an on-off switch for a fuel pump relay. General principle of operation is still the same. Just checked the readings of my replacement sending unit and it seems to go from 0 to 90 ohm sort of linear between 0 to 90 PSI even though gauge reads only up to 60. There are also some quirks like the resistance changes in noticeable steps and there is a visible hysteresis between pressure going up and decreasing.

[@American-OutdoorsNet]

Glad to hear! Thanks for tuning in.

[@rimfireshootingmk]

My pressure dropped to almost zero the other morning on a 65k mile GM Goodwrench motor. Got a new sensor and sender, did the tests, everything. Made me think it had to actually be the oil pump. For fun i pulled the bezel and then the oil pressure gauge. Put the oil gauge back and then started. Pressure was back. Cleaned, contact greased and polished everything. $73 in new sender and sensor too but i didn't have drop that pan.

[@nickvivid]

Thank you for this video. Helped me troubleshoot a shorted sensor wire on my G10.

[@American-OutdoorsNet]

Glad I could help and thanks for watching.

[@pauldavies9464]

Great video explained all very easy to understand just got to fix my Rover P5B now so I can see some oil pressure the Buick engine

[@thisguytrucksoldtrailer6875]

Thanks, this helped a lot.

[@andygreen1769]

Great vid!

[@Keeterbob]

Ok. I just installed a new sensor. With the car running and the tan wire disconnected I get 86 ohms from ground to sender lead. At idle. I know pressure is good. Tested with mech gauge. Is 86 high for idle? Mech gauge had pressure at 26-30. It’s on an 88 Camaro with a 5.7.

[@American-OutdoorsNet]

Did you check the sending unit prior to installation? What is the dash gauge reading? Go back to the 7:50 second mark of the video.

[@Keeterbob]

4.3 ohms. But I think I found the issue. At the gauge I am getting the same ohms that I am at the sender 86-92. This leads me to question the gauge itself. It’s not getting the signal from the sensor. I unplug the signal wire and the needle pegs. Plug it in it barely comes off zero

[@willuhl2086]

😊😊😅

[@omfgursodumb]

Hey thank you for the video. I was hoping to ask a question or two. I bought an 84 c10 with the factory 305. The guy i bought it from did a lot of questionable work. Im. Currently trying to figure out my oil pressure Guage. Looking around in my manual oil pressure sending unit with a tan wire and a pressure switch. I believe i found the wires for them. Do they both hookup to the same spot next to the distributor? In the spot i had a pipe nipple capped with a valve stem core remover lol

[@American-OutdoorsNet]

There should only be one wire with a small rubber boot (if OE) that plugs into the sending unit next to the distributor. It is in the wiring loom running behind the egine.