strange electrical problem w/ elec fuel pump-

[raxley]

I wrecked my Dodge 2005 2500 w/ diesel and until recently was going to part it out. Now it looks like I'll fix it. Right now I cannot get the elec fuel pump working. I have it set up with a pressure switch (from Richard at Glacier) which turns off pump when system is pressurized. At that point the mechanical pump takes over and the elec pump is only used until fuel system reaches whatever pressure it's set at. It was working well for years, but I cannot seem to get it running now.
My question is why/what would repeatedly turn power off to my elec pump after a few seconds after I turn key to on? I can hear a 'click' when power to circuit is turned off. It acts like a circuit breaker going off each time. In addition, the elec. pump never turns on.
I have to either get the elec pump going again or the mechanical one if I hope to start this. I cannot get fuel to engine w/ mech. pump, I guess because there is so much fuel line, 2 filters, and a very long run for both. Fuel comes from tank to a small strainer, then goes to mech. pump attached to balancer, then it goes through 2 fillers and then turns around and goes to the stock filtration canister attached to intake manifold. I did call Glacier Diesel (who sold me this 10+ years ago) and it turns out the owner, Richard, has sold it to new people. The guy I talked to nevertheless got all my information and will talk to Richard about this. It says in install manual that the mech. pump has grease in it to enable it to 'pull' vacuum the first time (of course the elec pump is there to, so it's probably not needed w/ elec pump). Although I've filled the 2 filter canisters with diesel I can't get it to start. I've even hooked up a motor that turned over the mechanical pump but it won't draw, or draw enough to 'pull' fuel.
I hesitate to also fill the stock fuel filter canister, I've been told it's too dangerous to bypass this last, probably most important filter, in order to protect the injectors from debris. Possibly I will have to do this, would this be enough to keep engine running until mech. pump fills it's system?

 

[raxley]

The plug that goes into the fuel tank sending unit/fuel pump has 4 wires. The two outside control the pump. If I connected 12v to one of the outside wires and grounded the other, the pump should run, correct?

 

[User113]

Before putting 12v to the pump wires, use a test light to see if 12v is present at the plug. If not, trace back to find out why. If so, investigate the pump.

 

[raxley]

Before putting 12v to the pump wires, use a test light to see if 12v is present at the plug. If not, trace back to find out why. If so, investigate the pump.

Thank your for the advice.
My 12V is another problem. I'll have a mechanic fix it if I haven't fixed it by next Monday, that's when I drop truck off there. My power that goes to fuel pump 'clicks' off after about 5 seconds after I turn the key on. If I turn the key off, I have to wait about a minute. Then turn the key again to get a few seconds of power. When it goes off, there is a fairly loud click, that comes from under the passenger side battery box, and there's a lot of stuff attached to that box-that's why I haven't lifted that box out yet. It's like a circuit breaker than clicks off, but then resets itself after you turn the power off. Difficult for me to understand what is going on.
There's a fuse for #39, which is for the fuel pump. It isn't affected, and still works.
I'd like to get this thing running so I can have them start on body work or DO something with my truck. I figured, if nothing else, I can make sure fuel pump works (or doesn't), also I want to 'go over' my wiring that I did 10+ years ago to put the Glacier system in. You can't get to the space where the plug goes into tank w/o taking tank out. I just took tank out today.

My idea if the pump is good, is to run another temp. circuit (w/fuse of course) that would get me diesel at the engine. 'Good' thing about all this is that I'm the only one who worked on the truck, and I pretty much had a plan with the work I did. Not like my 1994 Dodge Cummins, which has had everybody in the world (it seems) work on the wiring doing their 'own thing'. So the electrical 'glitch' will probably get fixed by the mechanic if I haven't figured it out by then. (The glitch where the power to pump only comes on for a few seconds before turning off. )
I will do that first, see if I have power (even briefly) at the pump. I'll see if pump works. I'll 're-do' my wiring and make sure nothing came undone or is grounded out somewhere where I worked.

I was wondering if I got the positive and return wire mixed up if it would hurt the pump. But you reminded me that I'll check where power is coming in at the plug so I'll get correct connections the first time.

 

[User113]

The ECM will energize the fuel pump for ONLY 10 seconds or so at "key on" unless the truck starts. If you're getting 12v to the pump plug for those first 10 seconds, all is as it should be electrically up to that point. If you have no fuel pressure or flow during the time the pump plug is energized, there is something wrong inside the tank. Independently putting 12v to the plug won't do anything.

 

[raxley]

The pump 'runs' (can hear a whine) but nothing comes out of the two tubes (out diesel and diesel coming back) I took the pump out a couple of weeks ago, because I wanted to drain the old tank completely (10+ years old) I guess I should look inside, what could I have done to that pump then that keeps it from pumping? Nothing I can think of.
So it appears I can replace the pump and hopefully get the truck running-it will save a lot on tow bills.

 

[raxley]

I saw your message after I posted. That is certainly good news! I wondered (and hoped) it was something like that!

 

[User113]

Actually, I just checked my Owner's manual, albeit for a 2004. The manual states:

2. Crank the engine for 1 to 2 seconds. If the engine does
not start, then release the key or starter button back to the
RUN position (do not turn the key back to the OFF
position). The electric fuel transfer pump will continue to
run and purge air from the system for about 25 seconds.
After 25 seconds, attempt to start the engine again.​

 

[raxley]

I was going to run a separate circuit for the pump. That's a BIG help, for letting me know what is going on!!
I'll go out tonight to pick up another lift pump from Napa!

 

[User113]

Looks like you're going to be dropping the tank again. If the pump is whining, there may be a kinked or disconnected hose; look into that before dropping $$ on a new pump.

 

[User113]

I can't type fast enough to keep up...

 

[raxley]

Your typing is FINE.
I already pulled the fuel tank, it's just a question of getting the right pump, apparently there were 2 size tanks that year, 34 and 35 gal. So I'll give my VIN to the dealer and they can tell me which is mine.
Thanks VERY much, you made my day!