The 1947 - Present Chevrolet & GMC Truck Message Board Network - View Single Post - 1986 C20 1ton dually conversion Check Engine Light

kristian_dancer · 10-08-2011, 02:36 PM

Can anyone tell me what the check engine light on the 86 c20 is wired to, as in what can set it off.

If it's only for smog fine I will not care and remove bulb.

If its trans temp, fuel pump or oil pump or something vital I will have to start traceing wires.

There is no ecm plug that i can find under the dash i have removed most of it in the search.

There is a group of fuses all good.

The carb is electronic.

There is a sensor on the top of the manual transmission. I replaced the trans oil which was a cloudy light brown with new, light still on.

Oil pressure seems good, Temp seems ok,. runs ok, thristy as all hell but hey it's a 5.7.

Really running out of ideas.

I know the engine is a replacement but it seems to run ok. no obvious loud knocks or squeeks.

I really just don't want to be killing the truck without knowing it.

10-08-2011, 02:36 PM	#10
kristian_dancer Registered User Join Date: Apr 2011 Location: Douglasville, GA Posts: 15	Re: 1986 C20 1ton dually conversion Check Engine Light Can anyone tell me what the check engine light on the 86 c20 is wired to, as in what can set it off. If it's only for smog fine I will not care and remove bulb. If its trans temp, fuel pump or oil pump or something vital I will have to start traceing wires. There is no ecm plug that i can find under the dash i have removed most of it in the search. There is a group of fuses all good. The carb is electronic. There is a sensor on the top of the manual transmission. I replaced the trans oil which was a cloudy light brown with new, light still on. Oil pressure seems good, Temp seems ok,. runs ok, thristy as all hell but hey it's a 5.7. Really running out of ideas. I know the engine is a replacement but it seems to run ok. no obvious loud knocks or squeeks. I really just don't want to be killing the truck without knowing it.