The emissions light on my 1986 351W recently came on. I understand that it is triggered by mileage on this truck because it does not have a computer. As a responsible truck owner, I verified that my emissions system is still there, but I can't figure out how to re-set the light.

Thanks for any wisdom that you can offer!

 

FYI - I found this on Ask Question & Experts Answer You ASAP! Name Your Price, Get Online Advice & Help - Just Answer!. I'll have too try this later on.

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LIGHT - EMISSION - STAYS ON

FORD LIGHT TRUCK

1985 ALL LIGHT TRUCKS

The emission maintenance warning system functions with two microprocessor modules. One module is the inferred mileage sensor (IMS) and the other is the emission maintenance warning (EMW) module. The IMS module is not part of the emission light circuit. The IMS module sends a signal to the engine control assembly (ECA) at a predetermined time which then automatically makes appropriate internal emission control adjustments.

The EMW module is a timing device that turns the "EMISSIONS" light on at approximately 60,000 miles, indicating required emission system maintenance. 1985 light trucks built prior to January 1985 have a non-resetable EMW module and require part replacement if the "EMISSIONS" light stays on. Later vehicles are equipped with a resetable EMW module and can be reset as described in the 1985 Car

/LightTruck EngineElectrical-Emissions Shop Manual, page 18-6.
An additional EMW module is available and is used only for vehicles with approximately 30,000 miles. This module will ensure that the "EMISSIONS" light will still be illuminated as required at 60,000 miles. Locations for the EMW/IMS modules are as follows:

Model Location
F Series Left side of steering column on instrument panel support. It should be brown in color and faching the drivers side kick panel on the brace.

It will have a white sticker on it just over the whole(reset hole) you will need to hold the reset button down with a smal screw driver in the hole while turning the key on.

Read more: 1985 F150 :Emission Light on.Am told there is a ... - JustAnswer

 

The one in my '87 was found between the column and the radio, up by the door chime above the throttle pedal.

Easy enough to hold the button in at the corner of the box with a paperclip while you cycle the key to reset.

I found it called "extended useful life sensor" when I searched this site to figure out how to turn the emissions light off.

Hope this helps.

 

Yup, reset button, no problem or you could fix it like the previous owner of my F250 did: with electrical tape over the indicator window. I lowered my offer when I found that he was trying to hide an “emission system malfunction” Moron!