Check Engine Light On

[MattsLincoln]

well this morning i started my car and the check engine light was lit. on my old speedometer it was the temp light so i checked my coolant fluid filled it to the top and the light is still on. The light wasn't on wednesday when installed it it just turned on today. what could be the problem. Bad Thermostat maybe. what would cause it to light.

[1990LTD]

what color is the light? does it actually say CHECK ENGINE? is it a picture of an engine?

[MattsLincoln]

no it's an amber light and has the words CHECK ENGINE on it. No pic of an engine you can see the light on my readers ride thread on the speedometer. one all the way on the bottom on the left side of fuel gauge.

[sly]

and remember, he's swapped out the cluster for one from an 88 GM. so when he says it was the old temp light, it may very well be just that.

if that's actually the case... then the temp sensor for the idiot light is shorted or the wire from the light to the sensor is shorted somewhere.

[1990LTD]

as I recall the only time I got a CEL on my 88 GM, it was because of overheating. i would suspect wiring shenanigans before an engine problem.

[86VickyLX]

well this morning i started my car and the check engine light was lit. on my old speedometer it was the temp light so i checked my coolant fluid filled it to the top and the light is still on. The light wasn't on wednesday when installed it it just turned on today. what could be the problem. Bad Thermostat maybe. what would cause it to light.

If it came right on after you started the car, it's not likely it's cooling system related. Sounds like a grounded wire to me too.

[MattsLincoln]

were would that be located. and how would i find this short.

[Lincolnmania]

low oil pressure

[MattsLincoln]

scott it's not my oil pressure that's the engine light with the engine mark on it. this is just the one that say CHECK ENGINE which replaced my Temp Warning light on my old speedometer. i was playing around with the key turning it on and off and finally the light went out so i don't know what to say. i will see if tommorow if it comes back on if so then there is a problem. taking pics post in a few.

[MattsLincoln]

here is the 2 speedometers top is the new bottom is the old.

[GM_Guy]

Do all the other lights correctly correspond to function?

Any clattering coming from your engine? You can possibly rule out low oil pressure.
Could be a bad temp sender. Disconnect it and see if the light goes out.

Then disconnect the oil pressure sender and see if the light goes out.

If neither do it, get the evtm for both cars and compare wiring colors of the old, to the new to see what the engine and check engine light now correspond to. If you are lucky, they match up with your old cluster.

Alex.

[MattsLincoln]

i will try that.

[MattsLincoln]

well problem i belieive is fixed. i found out on my old spedometer it had a blue circuit board and the new one had a red circuit board i saw on the red circuit board that pin and pin 2 of the plug join together 1 controls the temp light and 2 i think had something else. well on the blue board those too are separate and don't run into to each other so i swapped over the circuit boards and everything is fine now.


pics







you can see where it joins into the circuit of pin 1.

[GM_Guy]

late boxes combined oil pressure and temperature into the ENGINE light. That is why people always ask if it was CHECK ENGINE (ecu trouble code) or ENGINE (low oil pressure or high temperature) (which correspond to pin 1 & 2 in the 89 cluster). On a CV with an oil pressure "guage" they would have been separate.

You got lucky that everything had the same general wiring. Thngs could have melted down for you.

Alex.

[MattsLincoln]

yep just takes some thinking on stuff. that's how i thought of switching the circuit boards would fix the problem and everything works as it should now.