I have a 87 ranger 2.9. No power at the fuel pumps. Or the inertia switch. I have power at the pump relay and it clicks. When I turn the key on. When I connected my test light to the sending unit it flash on and off. Is this right? Or should it be constant. I have checked for fuses and can not find any. I have the low(tank)and high pressure(rail) pumps. I am at a lost where to go now. Thanks if you could help with this problem.

 

Yes, the sending unit is a 7 volt flash. Also, the pumps are entergized for 2 sec. with key on. Got someone turning the key off and on for you or have a meter that registers hi-low voltage? Bet you have either a tripped inertia switch or a bad relay.

 

I will get the wife to turn key for me. I have already installed a new relay. Didn't help. Will a bad EEC relay cause the pumps not to work? When I disconnected the inertia switch. The plug that goes into it looked burnt. So it might be bad.

 

If the pcm was the problem, the relay would get power, but no ground. If the connector is burnt at the inertia switch, does not mean the pcm is the problem. More like a poor connection, causing high resistance. Jump past the inertia, for test purposes only, and see if you get power to the fuel pump. Again, have someone cycle the key for you. When you tested it at the inertia switch, did you get a momentary fire, if not, the relay is not being intergized. Check both legs of the relay, you have one that has power on with the key and the other is grounded by the pcm.

 

I had the key turned to on. Didn't cycle it. Had no power to either line to inertia. Will not be able to try again til Thrusday. Have to work. Will get the wife to help. Thanks for the info. Will post Fri. on results.

 

Finally got a chance to work on truck today. I put a jumper on the inertia switch.Still no power to the pumps.Had power from the relay. But not from the the other side. Could it be my ingition switch. Man was it cold out there.

 

Ok, back to the relay. The power you have at the relay, is it constant or does it flash on and then off? On side is fused through the ign switch to the fuse box to the relay, key on, power at all times. The other leg of the relay runs through the pcm relay and is momentarily grounded by the pcm to run the pump to prime the system. You will have power on both legs with the key on, but only grounded for 2 seconds to entergize the relay until you crank the motor.

 

I checked the wire from the relay to the inertia switch. Had power there for about two seconds than it was off. On the other wire to inertia switch there was no power.

 

Sorry I haven't gotten back to you. Sounds like a bad inertia switch. Try jumpering around it to see if the pumps come on.