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Fuel pump primes backwards wiring issue?

1268 Views 11 Replies 4 Participants Last post by  Rob_64-365
Hello all, i have a problem i cant seem to get fixed. I have an 87 Bronco with a 302 C6 transmission. Ill start by saying there has been several hands over the years on this truck and not all did things the right way IMO. A lot of the plugs and or connectors have been replace/repaired. When i try to start the truck (key in the run position) i can hear relays clicking but no fuel pump. When I turn the key to the off position the pumps prime as they should if the key was in the on position. Another thing is the self test plug isnt working anymore. When i plug code reader into it, it wont start to run diagnostics. I have replaced the ECC, distributor, ignition switch, starter, starter solenoid,fuel pump relay and the EEC relay. The plug on the ignition switch crumbled in my hand when I unplugged it so I am not 100% sure they are in the right place. Also the plugs for the relays were replaced and im not so sure that they are rewired right. In moving with the wires around on the deivers side fender well the fuel pumps quit coming on at all but started working again after a little more wiggling but still ran backwards. I feel like there is just a wire out of place or possibly broken somewhere. ANY help is GREATLY appreciated Im not sure how much more i can take on the truck geez
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Sounds like you need a good wiring diagram to reference for your year to figure out what you have going on. Hold tight, I'm sure @miesk5 will hook you up shortly. He has helped me out tremendously with technical items like this.
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Well it did run a little bit nut the timing was off a tooth I believe. I decided to puy ya start button inder the hood so i could start it from outside. On doing ghis one of the best stiluds brokenoff of yhe starter solenoid. So i got another one and a set of spark plugs. Installed edn the starter solenoid and they new plugs, hooked up all the plug wires and coil. Turn ghe key and no fuel pump again. This time its neither of them comes on. So about the only thing I know to do is starr checking wires again does that sound about right?
It would help tremendously if you could edit your post to correct all of the spelling errors so we can make sense of what you are trying to say? (I'm guilty of always editing because of this myself)

Sounds like you think the starter was off a tooth, but you did not say if you corrected it? Then you clipped in a remote start button. Then broke a stud off of your solenoid & you replaced it, but still have no fuel pump kicking on.

When you say the Ignition switch and inertia switch "appear to be working properly" in post 6, can you tell us how you are verifying this? Are you using a test light, or multi-meter to verify power/voltage on the wiring going to your fuel pump?

Sounds like a wire is feeding power to the fuel pump when it's not supposed to be. Like someone tried to jump the fuel pump, and never got it working right, and left it at that & you are left to try to figure it out, which is not fun, but it can be done by confirming voltages, tracing wires thier complete length, to find what is feeding power to your fuel pump when it's not supposed to.

I would think its shorting out when you put the key forward, if that's the case? Which leads me to wanting to know the confirmed voltages coming off the starter, and at the inertia switch, checking and cleaning grounds. One of these has power when it shouldn't.
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