My son just purchased a '94 F150XL with about 200K on it and it sounds like it has a cylinder(s) not firing and it's getting crappy gas mileage. We have replaced the cap, rotor, plugs, and wires but still have the same problem (found a ground strap loose from the engine to firewall and connected, too). I was going to see if any codes are stored, but my scan tool will not come on by itself when connected and the key switch is turned to the "on" position. Instructions said to check fuses to the EEC connector. We opened up the distribution box cover but the only thing stamped on it are the fuse and relay position numbers. Some fuses are missing and I really wish I knew what those slots go to. Would sure appreciate a link to some kind of legend. Thanks.

 

This is a 1995 & pretty sure my 1994 is the same.





Dash fuse panel

 

That sure looks like it. Thanks! (Appreciate the one for the dash panel, too. Printing in cover is so small.)

 

You might have a bad PCM Computer. You can open it up and check the caps for leakage or just replaces the caps. Replacement PCM Computers do not always work the best.

The PCM Computer is the number one reason for the code reader or scan tool not reading codes.
I dough that you have a scan tool as they are very high dollar items but the in result is the same if you have one.

 

Where is the PCM computer located? I'm using an Innova scan tool which can read OBD I and II codes and I'm connecting it to the EEC connector on the driver side inside fender under hood.

 

It is located as in the photos below.

You take it out between the inter fender and the fender after removing the front drivers tire. The center bolt in the plug is a 10mm socket size. You will also need to stick a broom handle between the fenders and there is also small nuts above and below the plug.




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