Ok I got the ignition switch problem taken care of. You bump the key and it would start and idle perfectly. Well I let it set a week (til I could get a new radiator for it) Put the new radiator in it and tried to start it. The fuel pump in the tank turns on and primes. The High Pressure Pump (HPP) on the frame rail does NOTHING!!! I jumped the terminals (little connector by the battery) I jumped terminals A and E to force the pumps to run constantly (so I could check for power) again the intank pump running but the HPP did nothing I tested for power with my test light. The Pink wire got a dim light and the Black wire got nothing (ground I assume). When I plugged the connector back into the HPP I heard a noticable power draw (you could hear the intank pump loose a lil power.)

Am I missing something? I hate like hell to go buy a new HPP if I don't have to. But I think thats what the problem is because there is power (dim light on the test light) to the HPP Pink wire.

But the last time the truck ran (Last Monday night) it ran fine and gave no indication of the pump failing.






By the way I am working on a 1986 F-150 4 x 4 with a 302 4 speed with dual tanks.

 

Well got the fuel pump working again. Nothing wrong with it! Apparently I have a serious grounding issue with the truck. Now every time I turn the lights on...it's like opening a box of Cracker Jacks, you don't know what you're gonna get!!! Sometimes the lights work, sometimes some of the lights work but most time they are all mixed up...

example 1: Turn on hazards and the front and rear lights alternate back and forth....

example 2: Put truck in reverse all the lights on the rear of the truck come on.


example 3: turn on left turn signal front works rear is not.

4: turn on right turn signal and the front right works fine and both rear lights and the plate light all flash..

All the lights on the front of the truck work fine ALL the problems now are in the rear. Seems to me that a bad grounding problem will cause these problems am I correct???

 

Well, it's time to check all connections in general. Make sure you have no loose terminals, connections, frayed wires, corroded bolts. Make sure you have no water in connections, fuse panels, especially if you've recently been in mud or water. Easiest way to see if the pumps are the problem is to get a battery, find the pump wires and rig them directly to the pump, see if they work ok. I've been chasing this too. I put an electric pump on my '84. I would randomly cut off on me, run fine otherwise. Wound up being a loose spade connector.

 

I don't see how bad grounds could affect things like you mention.

However... To check.

Use jumper cables as temporary grounds to test between sections.

Test between Battery and Engine, Engine and Frame, Frame and Cab, Frame and Bed.

There should also be a ground between Engine and Cab but as long as the Engine-Frame, Frame-Cab is good it's covered, Still a good idea to have one.

-Enjoy
fh : )_~

 

Happy to say that I found the problem!!! There was a broken ground wire in the back harness that allow power to backfeed and cause all my problems. I replaced the ground and all is good!!!!!!!!!!!!!!!!!

 

Wiring problems make me so angry, then feel so foolish when I finally figure them out.

 

I know what ya mena I was mad as h#!! til I found it!! lol