Brian Beaulieu

What does the engine oil light indicate?

I just got a new (from a salvage) cluster for my 86 951.. it's from an 87. Every gauge works properly but that light stays on.. along with the center alert (big red one at the top/center)

I've triple checked all of the harnesses..

I checked the oil level.. it's actually over filled.. (thanks quick oil change place!) could that be the cause?

Now.. i had the oil change done before i took out the old cluster.. and the light wasn't on..

I also did some cam gasket work.. again, the light wasn't on after that was done.

Is there some kind of reset or something? I'm not sure what would cause that light to go on..

Thanks

Brian

Badue

There are 2 wires that go to the oil pressure sensor. One controls the light(switch SPST), the other is variable for the guage. They can get caught or wear down behind that plastic cover at the back of the timing belt and make contact to the block or other ground this will cause the light to stay on. That's the only logical thing I can think of you need to trace these wires back from where they go into the sensor and see if you can find the problem.

Florida951

I am almost sure, that it is the fact that the 86 cars dint have the low oil light, The 87s were the first year to have it and the light is located on the lower part of the fuel/temp guage. Beacause the 86 car doesnt have the sensor the new dash has no reading from the oil level guage and therefore lights up.

Badue

Ah, yes I see now you are talking about the Low Oil light and not low oil pressure light on the oil pressure side. Florida951 is correct '86 cars didnt have the sensor for low oil. There are significant differences in the wiring of the two.('86 & '87) Assuming you have a US cluster it looks like the wire that is in the same position (pin 5 addtl' electrics plug) goes to the seatbelt sensor on the '86 harness. So all you have to do is buckle your seatbelts and see if it goes off. <img src="graemlins/c.gif" border="0" alt="[ouch]" />
I'm not making this up.

Brian Beaulieu

Wow.. thakns for all of the feedback!

Unfortunately putting my seatbelt on didn't
turn the lights off.. i tried all of the seatbelts.

Hmmmm... I have my old cluster.. (i got the new one because it was cheaper than repairing my speedometer) I suppose I could just swap the speedo/odometer .. and use that.. but I think this little problem would be interesting to fgure out.

Can I put a loop into the wiring to trick it?

I don't know what wires are what on this .. so I'm willing to experiment with any ideas you have.

Thanks again.. that was pretty resourceful

Brian

Florida951

yea changing the speedo is easy, even fixing your original one is cake specially if just your trip odometer stoped, all you need to change is a little gear(or glue it back together if you find the pieces). good luck. <img src="graemlins/jumper.gif" border="0" alt="[jumper]" />

Badue

Ok, I've never been beat by wiring problems. I have never seen the back of the cluster on these cars though. Apparently by looking at the wiring diagram there is a maze of cross concections on the back of the cluster though that the diagrams refer to as "add. electric connector". By tracing the other circuits that go to this plug it looks like it is just jumpering them from one terminal to the other somehow. Possibly on circuit board fuses like some other cars use. Now here's what you can do, If you can figure out which of these connections is 5 and 12 you can just cut the wire or connection between the two and that will kill the light. (see note below)(on the '87 cluster) You can see by the diagram that if you just pulled out the bulb for the low oil that the central warning light would still stay on. Let me know if this helps, if not I can pull my cluster and take a picture of the back to show you what to do. Pin 15 of the "A" plug going into the cluster is the wire that goes to the low oil sensor on '87 but this space should be empty on the '86 harness. That's the main problem I have with my theory, it looks as if maybe this light is dual function depending on what you find out from my note below.



red= proposed jumper to be cut
blue= pin that should be connected to nothing(15/17 Plug A LH cluster)
green=Low oil light and path to central warning light

NOTE: If you can determine that 5 & 12 are indeed tied together then look to see if pin 10 is also connected to them, If it is then the low oil light is probably being turned on by the oil pressure switch. Pin 10 goes right back to the oil pressure switch side (SPST) of the pressure sensor. In that case see my first post