water pump and oil sender

[Guest kennyw]

I did this post last night and now cannot find it. I installed a remanufactured water pump and while there decided to replace the faulty oil pressure sending unit. I got a hand full at the bone yard and tried each one. They read 0 pressure with the motor stoped and then went right to max pressure of 155. There were the sm. short senders not the one with the lg. flats for a wrench. So what is up with this???????? I finally had to put the old unit back in place as it does work most of the time.......The parts store wants $30+ for this sm. switch. Now afraid if I buy it it also will not work........answers....ken

[padgett]

Errr - what you got was a handful of idiot light switches ? Think there is a part number on the wrench flats.

[Guest kennyw]

padgett,,,,,all had the same 4 prong setup and [all] only plugged in one way. Do you still think idot light switchs????????????ken

[padgett]

Suspect so - Prolly a standard engine wiring harness reguardless. Seems like I recall an option on the TranSport that looked like a guage but just had two positions - 0 and A Lot.

Did you note what the dash looked like (assuming the motors were in cars). Know that most base cars rarely have oil pressure guages.

Ruminating further, since the '70s GM cars have tied the fuel pump to oil pressure - no pressure, no gas. So you need two switches in the sender. One to make at no pressure/open with pressure for the idiot light, and another that is open at no pressure, closed with pressure for the fuel pump.

On the Reatta, the ECM measures oil pressure and handles the fuel pump relay but suspect many cars just use some/none.

[Guest kennyw]

SO;;;;;;;;use a bad oil pressure switch and the computer will shut down the fuel. I never would have go there for a fuel problem.........ken

[Don B.]

The Reatta sender is for a guage. Most other 3800's use an oil lite.

So you go from a varible switch to an on/off switch . That's your cost

difference. It's going to be hard to find one, sometimes you just have to

cut your losses and spend some money.

The original posting was on the 16th Go back a day or two

[Guest kennyw]

Ron: cutting my losses right now is using the old orginal that reads bad from time to time. There was a post with the right part no. but this would be hard to find in the bone yard. Also the right switch is pretty hard to get out without the right factory tool. This driver is never going to be worth any more with a $36 oil pressure unit. Not a daily driver, just a few days a month to keep the battery charged. I have fixed most of the problems that haunt these vechicles. The famous G.M. clear coat is coming off and it needs a repaint. Not worth the re-paint and still runs to good to get rid of. I saw quite a few of the old

switchs with the flats for a wrench to get them out. I guess a lot of the G.M. cars did have a oil pressure guage. I guess I will now look for a oil pressure gauge and then look to see if the newer sender has been installed. No sense getting anymore of the on-off sendersssssss.........Ken