I have a 91 pickup 2.4L and the CEL does not light up. I can't remember if it has ever worked. I just finished a head gasket repair and I was wondering if any codes were present but I can't tell since the CEL does not work. (I have never checked for codes but assume my year/model does provide them through the CEL) I have verified that there are wires going to the Instrument Cluster for it and I checked that there is a known good bulb installed for it.

I check all fuses and they are OK. Only wished I had measured to make sure the bulb was getting power on the high side. Question - where exactly does the power come from for the CEL light? I assume the ECU provides the ground but I have never located the ECU. It probably is behind a kick panel. I assume that the ground for the bulb comes directly from the ECU?

Any suggestions on where I can find power/ground locations?

Thanks

 

I would start by checking your diagnostic connector. At least by '93, there is a W pin (between FP and E1). That's the GROUND side of the CEL. You can probably use a test light to B+ (I prefer an LED; just get a 12v led panel indicator as it will have the integral resistor -- remember that polarity counts).

 

OK Will do. I am pretty sure my diagnostic connector has those pins called out. So is W connected to the ECU pin W as well?

 

Yes. A-5 on a '94

 

Bummer there is no wire contact on pin W on my diagnostics connector. Makes me wonder if the CEL is not functional on the 91 pickup. Guess I maybe stuck with measuring voltage at cluster connector or getting into the computer. There is 12 vdc from pin Bp+ to ground on the diagnostics connector.

 

Turns out the gauge cluster I swapped a while back does not have the template for the CEL. What a bummer. Even if the light was on I could not tell because the fuel gauge backing blocks the light. Power and ground seem to be at the cluster connector so I may just have to jumper in a bulb to read the codes.

 

I have a little experience on the 89 and newer but I believe the cluster should be set up for the CEL light on it. Been a while since I have been into one though.

 

I don't remember what model year the cluster I installed came from. I am pretty sure it was an older year. The original cluster speedo broke and was noisy and that is why I replaced it. Was surprised to discover this cluster does not have CEL template.

 

I hooked up a bulb and it kept flashing so no codes. I ended up taking out the contact on pin A9 and moving it to pin A6 so now my CRUISE light is my CEL.