I have a 1994 4.0L Explorer that keeps blowing the EEC fuse. Everytime I turn the ignition to "on" the fuse blows. Is there a short somewhere, or is it a sensor?? Thanks

 

It could be a wiring problem on top of the engine. If it's fuse #8 30 amp, then it feeds the injectors, most of the sensors, and some of the relays. Most of the engine sensors and controls are fed 12 volt as soon as you turn the key on. The other wire going to the sensor is grounded by the computer when it wants to activate something. For instance the fuel injectors. They are all fed 12 volts all the time the key is on, by the circuit you are having a problem with. When the computer wants to fire a particular injector, it grounds the other wire leaving the injector which makes it inject fuel.

And the circuit that is blowing the fuse also feeds the computer power. What I would do I think is start unplugging stuff. If you suspect the computer, unplug it and see if the fuse still blows. If you think the problem is part of the wires going to the engine, see if you can find a plug and unplug that part of the harness and see if the fuse still blows.

 

I may be totally wrong, but I could have sworn I saw a TSB about the computer grounding in the holder against its rest. Was it computer body against inner fender??
I thought I saw it at www.motorcraft.com or www.fordvehicles.com. If I am incorrect in recalling that possibility, I am truly sorry.

If, in actuality, I am wrong, Franklin2's ideas surely have merit. (To be honest, even if I am wrong in thinking I saw that TSB, his ideas surely have merit!!)