Inertia Shut Off Switch "Help"

[n4baf]

What will cause the inertia switch not to put out 12V.
I'm trying to track down a problem with my 1993 Explorer.
The vehicle just stopped running while driving; I checked all the relays
and they seem fine. I don't hear the 3-5 second fuel pump noise any more.
I read many post where it says that you should have 12V on both wires
going into the inertia switch. I checked mine and have only 1.4 volts.
Please I need help.

 

[MrShorty]

You only 1.4 V (referenced to ground I assume) at either wire at the inertia switch? Then the wiring fault lies "upstream" of the inertia switch. Upstream of the inertia switch are the fuel pump relay and the fuel pump fuse and several feet of wires. In addition, if the EEC relay isn't closing and feeding power to the computer, the computer can't ground the fuel pump relay to get power to the pump.

I would suggest getting a wiring diagram and continue working back until you find the break in the circuit.

 

[n4baf]

Thanks for your advice. It worked and it turned out that the EEC 30 amp fuse was blown. I replaced the fuse and it started right up. Your insight changed my way of looking for this fault. What would cause this fuse to blow?

 

[MrShorty]

The EEC fuse supplies power to the entire engine management system with all it's sensors, solenoids, and computers. A short in any of those wires/components could blow that fuse.

 

[n4baf]

I have the same problem.My car ran fine yesterday but today it keep blowing eec fuses. Is there any simple test to find what is doing this.