Mallory 4140M

[Jetpilot]

This is a repeat post from the Product/Accessories Forum I just wanted everyone to see it.....





OK guys,



I am about to replace my stock lift pump with a mallory 4140M... But, I want to wire the pump directly from an electrical source using some type of relay. This way I can ensure proper voltage to the pump. Now the question to all who have done this, what type relay did you use and where did you locate it? How do I wire into the OEM wiring harness (from the lift pump) to activate the new pump? What other problems can I expect to run into during installation?



I am not a wiring genius so please be complete and simple with your explanations



Thanks,



Doug S.

 

[HVAC]

Brandon

Well Brandon just did this last week, maybe he can clue you.

 

[Bigsaint]

Doug, I'm now running with a relay with my Mallory, decided to go this route after the first one failed as a precaution. I bought an automotive 4 pronged 30 amp. relay from radio shack, though any auto parts store should have them. It's wired as such... run a fused line directly from the + terminal of a battery ( I choose drivers side) to the relay as the source, use the existing wire that powered the Carter pump to the relay as the switch (triggers the relay to provide power to the load), run the load wire from the relay to the red (+) wire of the Mallory (I ran a fuse in this line as well), run a ground wire from the relay ground to the frame and ground the black wire on the Mallory to the frame as well. I'll send you a PM with my home number, if this doesn't make sense pick up a relay and give me a call, I'll walk you through it. It's really not hard to wire in the relay ( this was my first and I'm hardly an electrical engineer). Give me a call if you need help.



Scott W.

 

[csutton7]

you can get the relay from jegs or summit also---I'd use the way Big Saint did it... chris

 

[blackbeast]

Doug,



You need a 30 amp single pole double throw relay, and a fuse holder rated to 30 AMPS, and some 12, or 14 gauge wire. The relay has 5 prongs as follows.

Supply

Trigger

Ground

Nomally Closed

Normally Open



You want to wire the supply to the main distribution block or the battery. I prefer connecting at the distribution block, as you don't have battery acid concerns there.



Next connect the ground lead to a good ground.



Connect the trigger to the 12 volt positive from the factory pump.



Connect the Normally open trigger to the new pump.



Leave the Normally open trigger unused.



See diagram below , and if you have any questions, you know where to reach me.

 

[redneckdr]

relays

relays are available at any parts store. 30 amp, generally in the fog light section. Federal Mogul DF005 is a good one, generally about $4. has 5 poles, but 2 are for the load, so only use one on most applications.

 

[Paul Somers]

I also want to install pusher pump at tank. But I want to eliminate the original pump on side of motor. What plumbing is needed to bypass original pump? My pump was just replace by DC, 31,000 miles. It was dead. Would not even make a noise. Only discovered it while replacing fuel filter. Would not prime. Only symptom was a slight bucking at low RPM.

 

[DiTrani]

Confused

I thought I read that the lift pump operated at 1/2 speed during startup. If that's the case, it must be done by regulating the voltage to the pump. Doesn't that mean that with a relay you are either not running the pump at all during startup, or running it at full speed, depending on if the reduced voltage is enough to switch the relay? Am I just all wet?



CD

 

[HVAC]

All Wet?

cditrani,



Don't worry about that different voltage stuff.

Beleive me, your engine doesn't care.



I've been running aftermarket pumps for two years now and at no time have I had a problem related to the alternate voltages.



Paul Sommers,



Mount your new pump on the outside frame rail and wire it. Then cut the supply line on the top of the tank and route new 3/8" (min) ID line to the inlet side of the pump. Then run new 3/8" (min) line up to the filter housing and your done.



I'd recommend a fuel pressure gauge or at least test it at oil changes with an external gauge.

We see WAY to many incidences of lift pump failure to not address this problem.

 

[SEmerson]

I just used the original wires and bypassed the lift pump then I went to my mallery. No problems yet and real clean.

 

[Paul Somers]

Thanks for your reply Novell. My input to lift pump trouble. The ones that are'nt bombed are not safe either. I thought bombing was causing the problem. Wrong. My truck is basically stock and babied. Retired and this truck has got to be fairly in-expensive to operate. My lift pump went completely dead at less than 30,000 miles. That was a warantee but the next one they tell me will be mine. These pumps are such a piece of crap; they should have to do something about them. Do F**d have lift pump? Do they have problem? Do 12V Cummins with P7100 have lift pump? Do they have problems. I have friend with old 6. 5 GM with 190,000 miles and don't think he has replaced lift pump. There, I feel better.