Lift Pump wires no power

[xtrempickup]

Not showing any signs of power at my lift pump. checked with my test light the wires connected and truck running and checked the wires disconnected from the pump. i replaced this and the Oil pressure switch about maybe the most a year ago.When i checked the wiring them it had power and i take it the pump was working as the truck responded a 100% bettter than before it when the truck could barely start when cold. oil pressure on the dash shows excellent at idle and cruising. any place i can draw 12amps and run a jumper to the pump and see if its good , obviously 12amps that wont run continuously, just when the truck is on? i dont want to play with the ignition wires as these trucks have enough problems with them as it is without me touching them. can i pull from the alternator? any ideas

[joe bleaux]

Just clip on a wire from the battery for temporary check; a load will only draw what it needs, unless something is shorted.

Joe

Not showing any signs of power at my lift pump. checked with my test light the wires connected and truck running and checked the wires disconnected from the pump. i replaced this and the Oil pressure switch about maybe the most a year ago.When i checked the wiring them it had power and i take it the pump was working as the truck responded a 100% bettter than before it when the truck could barely start when cold. oil pressure on the dash shows excellent at idle and cruising. any place i can draw 12amps and run a jumper to the pump and see if its good , obviously 12amps that wont run continuously, just when the truck is on? i dont want to play with the ignition wires as these trucks have enough problems with them as it is without me touching them. can i pull from the alternator? any ideas

[xtrempickup]

i was told that the lift pump should run as long as the truck is running. i was under the impression it was a keyed type operation and it needs a constant 12 volts to operate.

[joe bleaux]

Well, if you are wanting to know if the lift pump works, unplug it from the connector and following polarity, simply supply 12 volts d.c. to it.

I am new on here so, I don't know too much about these trucks but, what I said above will apply to any vehicle with a 12 volt pump.

I do THINK that you are correct that the lift pump runs continuously when the engine is running however, I THING 12 volts is supplied from a separate source during start up.

Joe


Joe

i was told that the lift pump should run as long as the truck is running. i was under the impression it was a keyed type operation and it needs a constant 12 volts to operate.

[xtrempickup]

i can test if it works , i'm looking for a way to by pass and run a new hot wire for it so i can make sure its working so my truck runs properly. i was looking for a 12volt source that will come on at key and off at key

[Artworks]

You want to tap into the fuse box on the side of dash, little fuse makes a nice little adapter ' mini tap' that lets you tap into and supplies with a nother ciruit. I installed a switch to use temporary, to find out source of my problems, It was the OP switch again, only 1 year old. S o I got the relay and new OP from Kennedy, all problems solve, Re use of the temporary toggle switch to power up my box 'topper' lights. You realy don't want to supply the lift pump with constant ( Keyed or not ) 12V, cause if truck is not running, this thing is pumping fuel, a real safety concern if your in an accident or just checking wireing, lights and accessories.