: Where is the oil pressure switch located - 84 Deville HT4100

08-06-11, 05:14 PM
I'm trying to replace the oil pressure switch on my 84 Deville HT4100 due to DTC's being set off, however, I don't know where it is physically located. Can anyone tell me where to find the little sucker? Picture is shown below...


08-06-11, 05:46 PM
It is on the side of the oil filter adapter.

08-07-11, 04:14 PM
How do you get the old one off? There's no wrench that fits - and there's limited space by the thing. Do I take a vice grip and just try to unscrew it????

08-07-11, 04:18 PM
should be 19 mm and/or 3/4 inch bolt head

08-08-11, 02:55 AM
This one was tough....I fought with it all weekend.
I measured the new one I had, and it would take a 1-1/16 DEEP socket. (at least for this vehicle). The electrical pins make it so that a regular socket isn't deep enough. Of course, I don't have a deep socket that size so I tried whatever I could get to fit: an adjustable wrench, pliars, vice-grips etc. What finally ended up working is taking a long screw driver and a hammer, place the screwdriver in one of the notches and tap, tap, tap away until the little thing starts to turn. We finally got it loose and were able to remove it. :highfive: