: Help-Broke Oil Pressure Switch wires while replaceing CKP's 03 Deville

01-06-13, 07:50 PM
I have the connector in my hand. Can only see one wire at the harness but the connector appears to have 2 broken off wires. Where do they need to be connected to? I found a part number for a replacement harness 12085539? It seems to have 4 connections but I don't have to use all 4 obviously if this is the right part. The car has 185,000 miles and was dripping oil among other things before I got the 340.341 & 385 codes and whent and replaced the Camshaft Pos Sensor as well as both CPK's(As long as I was in there, I was going to replace both) When trying to reconnect the New engine oil pressure sensor I just was not able to get it on easily(Heat Malformed latch didn't help) and next thing I new I had a connector in my face. there is very little wire on the connectors so it would be pretty hard to solder anything on there. Besides, I can only see one wire coming out of the harness. I need to Know where both wires were connected so I can reconstruct. It looks like (from other posts) that I will get a shut down now from the DIC if I run as is without the connections. Is that true or will I just have an idiot light on the dash? The engine has never had any oil pressure problems of any kind.



If there is a shut down now in DIC and chimes do the chimes stay on or just appear in intervals??

01-06-13, 09:28 PM
It won't shut down. You'll just have to live with the oil pressure warning message.

I just searched the FSM for a schematic containing the oil pressure switch for :20 minutes and for the life of me, could not find it.

01-06-13, 09:39 PM
Relax, all hope isn't lost.

You're in the "D", there are from what I hear PLENTY devilles there.

Go to a pull a part (if they have one) and get under the car and cut off the connector you need. Make sure you get PLENTY of extra wire on the connector so you can solder it or butt connector (yuck) back into place.

I suggest wrapping up the connections in electrical tape and then putting plastice wire loom over it for added protection.

01-07-13, 04:34 AM
Same here. I subscribe to Mitchells and can't find anything that will tel me which wire went where.


They do sell a plug with harness for little more than $20.00. But, I can only find one wire. I really need to know where they were connected to. Being in the detroit area there will be some wrecked devilles out there. NOw if I can just get under one and see how it is wired.

01-07-13, 08:30 AM
They do sell a plug with harness for little more than $20.00.  But, I can only find one wire.  I really need to know where they were connected to.  Being in the detroit area there will be some wrecked devilles out there.  NOw if I can just get under one and see how it is wired. 


I found a reference that says there are 2 wires, one Black w/tan and the other Tan w/Black So if I pull the insulation off of the harness in there a bit, hopefully I"ll find those (2). They sell a Pigtale with connector that has 4 wires coming off it. I guess I can just use 2 and snip off those not needed Alternate/OEM Part Number(s): 12085539, 433

01-07-13, 12:15 PM
It's an on-off switch. Makes no difference which wire goes to which pin.

here you go..........

01-07-13, 03:13 PM
I found that, but I though he was asking where the wire goes to on the other end.

01-07-13, 06:03 PM
Excellent. Now the question has become what would happen if I could get the two connected by slipping a splice sleeve onto both would that defeat the light or chimes? Is there a fuse just for this? Is there access to circuit 231 somewhere that I can run a wire to easier since the other connection is just a ground? They are short and there's so little clearance that after an hour and a half I havn't been able too splice the new connector(bought a Pigtale from O'reilly 12085539). I just can't get hold of the wires in a position where I can slip in a second set of needle-nose and get it to clamp. I can't get enough leverage, I have to use mini-pliers to hold the wire and then need the piggy-back-or double-length regular needle nose to reach in to try to pinch. I just can't get enough leverage. I bought the "Flip" splices but there is just no way to get both wires in there and get it closed. I did try glueing the first wire in place(plastic to plastic) hopping that that would be half the battle but I can't get it closed on the hanging wire.
I must assume they have some kind of "unhook the exhaust, manifold and jack up the engine" -kind of service procedure for this.


Mitchells wiring diagram shows the switch in the closed position, I believe. If the arrow moves to the alternate position it is open. Does this mean that the normal running condition of the circuit is closed? Therefore it seems like you could defeat the warning lights if you could slip a splice over both wires. I don't know if that's even possible because of the leverage issue but I'd like too know now before I put the Oil filter adaptor back on and have absolutely no access.


It does seem logical that it would be closed for running because if it was open and something became disconnected, you wouldn't get any warning, the system wouldn't know the difference. Seems like they would want something to happen when a wire came loose.

01-07-13, 09:08 PM
Mitchells wiring diagram shows the switch in the closed position, I believe. If the arrow moves to the alternate position it is open. Does this mean that the normal running condition of the circuit is closed?
Don't hold me to it, but I believe so. I think it is much like the brake wear indicator. Open the switch and you open the loop (circuit) and trip the message.

01-07-13, 10:44 PM
Well it's hard to tell if I got a bad connection(It looked like just a few strands were touching) or if the computer is smart enough to know that crossed wires are not a sensor because I have the Low Oil Pressure-Shut Down Engine Message. Unfortunately my fuel guage doesn't work so I have been using the Fuel Used message in the DIC to tell me how much gas I have. The Low Oil Pressure message has such priority that it won't let any of the other messages through unless there is a technique I haven't tried. I did try to Up/Down arrow to the next message-no dice. At least there's no sound to go with it. I guess that would include the Oil Life Message too. It might be possible for me to knock loose the splice connector that is connecting the Oil pressure switch if I knew for sure that that would get rid of the message.


Do any of the handheld scanner tools allow you to turn off warning messages like that? I don't have one-I just use my Dash for the Codes(2003 was last year for that)

01-08-13, 02:08 AM
To fix your issue properly you will have to disconnect, the a/c compressor, crankshaft postion sensors, front oxygen sensor, oil level switch and some harness retainers.

Once all of that is disconnected, the harness can be pulled up by the water pump housing so that you can make the necessary connections.

If you bought a "used" connector from the same year vehicle, the color of the wires should match up directly.

01-08-13, 03:46 AM
I think this switch works the other way: it's closed if the pressure is low. Or maybe I'm totally wrong, but look at my post and let me know if what you see matches what I found: http://www.cadillacforums.com/forums/cadillac-seville-cadillac-eldorado-forum/258449-help-oil-pressure-low-stop-engine.html#post2970877

01-08-13, 09:45 AM
Here's a broken open Northstar oil pressure switch. Above about 5 psi the contacts open. The threaded metal base is on the left, the contactor and connector is on the right.

Look at this electrical diagram - the EOP opens with pressure. (Sorry for thumbnails - click to zoom)

01-08-13, 09:20 PM
Thanks a lot. That's very useful. I'll just remove my splice(The folding plastic snap-closed kind with metal clip inside) and tape the wires off separately. I should be able to get tape on them even as short and hard to reach as they are. I've got nothing to loose as I'm getting the message, an occasional chime, and the loss of the use of my DIC.

Thanks for all the help, everyone. Nothing is going to waste as I will probably go the harness from the junk yard route or just remove my existing harness enough so I can soldier a new EOP sensor connector when the weather warms again in the spring and I can get someone to help me. It's funny how daunting and complicated these things seem when you first go at them and how simple they seem after you're done.

01-13-13, 11:50 AM
CONFIRMED-Leaving Engine Oil Pressure Switch Wires OPen-or Disconnected from anything and each other allows everything, Including DIC to work fine. No Warning Bells or Lights like I got when I hooked them together to "Bypass" the switch. Yes this leaves you open to not getting a warning about a Problem with Oil Flow. But I will fix the switch connection on the harness when the weather gets decent. I bought a Battery Soldiering Iron and will get some small wire clamps from Radio shack. The problem is not having enough hands or room. When you're on your back with the car on ramps the EOP switch, motor mount starter motor oil filter & housing are right in your face & no room for anyone to help you by holding the wires in place while you soldier. But I'll get it. Thanks evryone for your help on this. Hope this will come up in searches as I seriously doubt I'm the only one to have the Engine Oil Pressure Switch Connector break off it's wires.