I am trouble shooting a no start issue on a 86 ranger 2.9l pickup. I have no power to the inertia switch and need to know how it is powered and from where. Would love a wiring diagram if possible.
I have battery power to both relays and koeo power also but the pumps do not run. If i put 12 volts to one side of the inertia switch the pumps do run.
Thank You

 

Here's a diagram.



Check the darkgreen/yellow wire leaving the relay.

 

thank you very much

 

still do not understabd where the power to the inertia switch comes from, does the ecm power the relay or is it powered from the fuel pump relay?
Where does the signal to energize the fues system com from?
Sorry for so many questions, but it has been many years since I worked on any fuel injected vehicles

 

Both.

Look at the relay in the diagram. The squiggly line is the coil of the relay. It receives power from the ecm relay all the time the ecm relay is closed. But even though it has power from the ecm relay, it still does not function. If you follow the circuit through the squiggly line, it goes to the engine ecm. This is the ground for the relay coil. When the ecm verfies the engine is turning(pulses from the dist) it goes ahead and grounds the lightblue/orange wire, which makes the coil in the relay energize.

When the coil energizes, this makes the circuit to the left in the little relay picture. This circuit is what actually sends power down to the inertia switch. It's fed from 30a fuse from the fuse box.