kennedy lift pump

[tnt1197]

In the box that came with my 97 K3500 is a kennedy lift pump, with wiring harness. The VERY basic instructions indicate completely bypassing the OE wiring harness and oil pressure switch. If I run the supplied switch, what other functions does the OE switch cover? 2nd, the pump data label claims 150 psi, will this cause issues? 3rd, the instructions say that the pump is not self priming. While i try not to run out, I've done so twice and I really appreciate not having to bleed out the fuel system after dumping in my safety can. 4th, should I consider cutting the line prior to the pump and plumping in a gasser inline filter, as it's a rotary vane pump? Anybody with kennedy pump installed. pros and cons appreciated Thanks

[GMC Hauler]

96 and later use a relay and the oil pressure switch in parallel to power the factory lift pump. While the aftermarket harness is nice and all, it duplicates what is done in the 96 and later, therefore in my opinion, not needed. The 95 and earlier needed the aftermarket harness.

The bleed switch: there is a red wire in the factory harness back by the underhood fuse panel that can be connected to the battery positive post. An alligator clipped jumper wire can do the same for much cheaper.

The 150 psi issue doesn't seem right to me. Ask Kennedy if this is correct. 150 psi is way more than is needed. Really, all that is needed is a minimum of 2 psi at full throttle. The higher the pressure, the more chance for a fuel leak.

[tnt1197]

Kennedy says 3 to 4 psi installed, 150 psi rating is max, ie regulated or common rail. The harness will now have a home on my 85.

[GMC Hauler]

Kennedy says 3 to 4 psi installed, 150 psi rating is max, ie regulated or common rail. The harness will now have a home on my 85.

Good to see the harness will have someplace to go where it is truly needed.

Is the pressure quoted at full throttle or all the time? I have considered one of these pumps for some time, but am waiting for my current pump to die.

[ronniejoe]

I'm not familiar with the circuit for the later models, but my 95 has a relay also...

I like the harness because it has the manual over ride button for priming. That is not on any of the factory installations...

[GMC Hauler]

I like the harness because it has the manual over ride button for priming. That is not on any of the factory installations...

in 96, they don't have a button, it's a wire. It's terminated with a push connector, hence the alligator clipped jumper wire comment. That can be used for priming, and it is factory installed. It's mentioned a few places in the board, at least it was a few years ago. That's how I found out about it. ;)