tommurray

94 doge ram 2500 4x4 12v diesel
according to dodge factory service manual when checking the gauge side of sending unit you should read 65 ohms or more from pin to sender housing. recently replaced sender and that did not fix low gauge reading, new sender does not read anywhere near 65 ohms, more like infinity or open. took it back to exchange for another one and brought my meter w/me to test the next one and reads the same. w/mechanical gauge mounted on oil filter housing pressure is 60 psi at idle so i know i have ok oil pressure. i tried several parts stores ( took meter w/me) and they all read same (no where near 65 ohms) i don't know if a cummins part will be any different. the gauge on the dash reads about 40 lbs at idle and wont go up much from there, but does go down some once engine is warmed up. tested the gauge according to manual and it tests ok. anyone come across this before

torquefan

I can't find this test procedure in my manual, but does the 65 ohms represent what the resistance should be at 0 psi, or with the engine running? Just wondering if they may have made an error writing up the procedure and the 65 ohms represents a resistance at a certain pressure you would see at idle.

tommurray

yes it says 65 or more w/engine off and the resistance should drop to between 24.5 and 65 ohms w/engine running. its in section 8e pg8

1320

For years I had my oil pressure drop off after a freeway cruise....to 0,......and the check gauges chime and light come on everytime. I always meant to change the sensor but I new it was false (checked with mechanical gauge). Well I NEVER did change it, but I did have to change my pcm......(for another reason) and voila the oil pressure gauge is fixed.