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So i did some searching and didn't see a similar problem..... Im finishing up putting the luv i bought together. The problem is when i flip the key to the on position the starter takes off, but if i pull the fuel pump relay it doesn't do it... Any thoughts?

Has the fuel pump been rewired/bypassed by a separate circuit? If the fuel pump has power separately it would feed back through the relay to the starter solenoid.

Solenoid on the starter could be stuck, pulling the relay would kill the power to to entire system. Try tapping the starter solenoid with something...

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FIAA!

SFPP!

Egg's analysis is dead on I believe.
Once while putting a new fuel pump on one of my trucks I did the exact thing he descibed,hooked a different hot wire to the wire coming from the relay and the truck started cranking over,scared the crap outta me...

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Will try that here soon thanks!

I just re read what you said and im not sure if it has been bypassed. So if they say put it on a switch straight from the battery it would cause it to do that?

I wacked the solenoid and the starter itself with a hammer and no luck there. If the fuel pump relay is toast could it back feed to the starter solenoid?

Yes, applying power to the fuel pump will back feed through the relay to the starter solenoid. Will do this with a perfectly good relay through its normally closed contact. So if a manual switch is used, just pull the relay.
This is all wired this way from the factory for safety reasons. In an accident the motor will stop, alternator will stop charging, relay will open killing power to the fuel pump, therefore preventing a gasoline fueled fire.

Yes, applying power to the fuel pump will back feed through the relay to the starter solenoid. Will do this with a perfectly good relay through its normally closed contact. So if a manual switch is used, just pull the relay.
This is all wired this way from the factory for safety reasons. In an accident the motor will stop, alternator will stop charging, relay will open killing power to the fuel pump, therefore preventing a gasoline fueled fire.[/quote]



Ok i was confused and thought the starter worked off the relay too. I'll start looking around at it in the am. Thanks

It will not back feed to the starter. Remember a relay uses a low amp power to pull a magnet down to energize a higher amp load. By adding power straight to the fuel pump power will not jump to the pull down side of a relay that in this case is on the start circuit.

Think of it this way, on a starter like ours the battery is connected to the starter at all times, if your theory is correct then power would back feed to the starter switch, the starter switch only energizes the starter solenoid and never cross feeds to the main battery cable. It only pulls a magnet to contact the main battery power to the starter motor windings.

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Take another look at the wiring diagram, (the 79/80 diagram is the same cirtuit but much easier to read). With the fuel pump relay in the "relaxed" position the starter solenoid and fuel pump power is connected together. This is so the fuel pump will run in the "start" position of the ignition switch. So--no mater where the power is applied they both are energized.
After the engine starts the alternator charging pulls the fuel pump relay contacts open, disconnecting from the starter circuit and connecting to the alternator/voltage regulator circuit.
Kind of a complicated circuit I know, but that is how it works. Luv fuel pump circuit 101.

I see what you are saying but I have jumped several LUVS fuel pumps and never energized the starter.

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I've had this happen on 2 LUV's,my old 79 and the 76 Green Machine.

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"You can't please everyone,so you've got to please yourself"

Well aside from dropping the back of the cab off the Jack stands i think i got it figured out..... The ignition. I hooked the fuel pump up and with it running it didn't energize the starter in the on position... At first then after i tried it a few times it would do it randomly. The ignition cylinder seems a bit gummed up and i think it might be the problem cuz now it wont even turn the pump or starter on. I think i have a spare in the parts bin that i would have to re key

Tif it did energize the starter then the by pass would be energized and the truck should start

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As long as the starter was disconnected the fuel pump would operate normally so i wired in a push button start

I've done the same with my luv... Wen I ran a hot wire into the fuel pump circuit. So dont tie n2 it, it has to have a closed circuit so if u hotwire the pump make sure that 1 endor the other is cut in the circuit.