LUVTruck.com

My oil light comes on at about 800rpm, and goes off about 950.

Looking to know what the psi has to drop to before the light comes on.

Some DPO had it disconnected when I bought the truck, so the oil light wouldn't come on. I found the lead tucked away in the wire loom when I was cleaning the engine compartment.

I know that the light should never come on. If I know what the set point of the switch should be, then I can figure out if someone put in a wrong switch sometime in the last quarter century, or if I need to replace the oil pump.

The switch likes to see 4 to 7 psi. Any higher or lower and the indicator will light up. Try replacing the switch first before you do anything crazy. You can find it at PartsAmerica, Napa, Autozone, etc... Good luck, RF

Anything below 4 - 7 pounds of pressure and the light will come on but pressure higher than this will make the light go out.
If a new oil pressure sending unit corrects the problem, great, if not you might have worn main bearings and or weak oil pump.
Good Luck

_________________
Fitzworld
A driveway full of Full size American 4x4 iron and one
LUV Diesel long bed

Running oil pressure--if you can guage it--should be about 56 PSI according to the Series 9 shop manual.

-DK

Ok, new sending unit in. 10 psi at operating temp, 50+psi at speed. Thanx!