On my '70 stage 1, my oil pressure gauge has decided to stay pegged from the time I turn the key on, till the time I turn it off. I put a test light on the positive side of the battery, and on both the body (engine block side) of the sending unit, and the wire lead side, I have continuity.....which, in turn makes me think it is stuck closed. Can these be cleaned and serviced, or am I at the point that I should be looking for a new sending unit? Anybody have one NOS they would part with? John
I don't, but I had 3 sending units go bad in 5 years. I know originality is a concern to many folks, but what's so bad about a simple relplacement unit from NAPA? They are available. Put the non-NOS one in and get the car working, and go on a hunt for a correct NOS one is my advice- you'll get your part, but the lack of the NOS part won't sideline the car. Then you simply install the NOS one later, and keep the NAPA one as a spare
Original GM part No........ My local Auto parts suppliers are possibly lazy, and less-willing to research (or unable) to find parts for older cars. If it isn't in the computer, then they usually don't know how to look up the parts in a book anymore (or unwilling). Does anyone have the GM part no. we can give them to cross-reference? I do in my assembly manuals, but they are loaned out and I am not sure when they will return. John
Go to your local NAPA/UAP store. Get part # OP6650. 0-80 PSI as the originals had. Looks identical. Many of the after-market products are scaled 0-60 PSI.
Thanks Thanks Craig, Got the Sending Unit, fit and looks fine.....but, didn't fix the problem. Gauge is still pegged when the key is on. I didn't touch/move/or change anything in the wiring harness inside the car, only under hood. I had the engine out for cam/lifters and put it back in exactly the way I pulled it out. Neither the oil pressure or temp worked so I assumed it was a ground issue. I took care of the ground, and the temp gauge works fine now. Still no luck with the OP gauge. I pulled the wiring harness with the engine, it's easier that way, and plugged it all back in carefully as I put it back in. I know that none of the wiring got pinched.......so, what do I check next guys? John
Found It!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !! Well, it appears that when we thrashed all night to put the engine back in the car, upon plugging the harness back into the firewall, I got it ever so slightly crossed up, and bent one of the wire tabs over. Guess which one? Bingo, you've played this game before haven't you? :rant: It was grounding against another lead (which was also a ground) and kept the gauge from working properly. Now I have a NEW sending unit in my car that I really may not have needed. Glad I didn't step-up and purchase an NOS switch at a grossly over-inflated price. ou: When will I learn to look at the obvious things first? :Smarty:
Went thru kind of the same process recently with my car. Thought I had a broken weld in the floor, something loose....I didn't know. When ever the weight of the car shifted I'd get a bit of a clunk in the floor, by my left foot. Oil canning sound. Feel the clunk on my foot. Had the car in the air a few times looking. Tightened everything I could get a wrench on & then some. Changed the small washers on the forward mounts with large fender washers...what a job that was. Noise still there....getting to think the whole front clip would fall off any day now. Turns out the lower drivers door hinge has a post to which is attached a roller. The roller rides on a bar with detents for half open & full open holds the door where it is. The roller & bar were very dry. Couple drops of oil & problem gone.
