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KD lift pump harness install question

4

4thesporty

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Location
DFW....Texas
I am trying to finish the installation of this harness. I have the tee in the OPS hole. The original OPS plugged into the factory harness, and the OPS provided in the kit plugged into the relay.

Then the relay is wired to switched 12V and the + side of the battery.

When I plug the lift pump into the new kit's harness connector it runs all the time. If I unplug the lift pump everything works as it should. I can push the manual button and the red light will come on (indicating power to lift pump), also I can turn the key to "on" and the red light will come on.

Then, if I plug the lift pump back in it runs constantly. What am I missing? It has to be something going on with the lift pump, right? But what?

In the process of doing all this I must have fried my original OPS as my oil pressure gauge is now reading all the way to the right. I'm going to go get a new one and go from there.

Thanks in advance.
 
Have you tried to call Kennedy?

He is very helpful on his products on the phone! :thumbsup:

What part of DFW do you live? I grew up in Southlake.
 
I am going to call tommorrow if I can't get this figured out tonight. I tried, but they had already gone home for the day, I guess.

I am in Burleson, just south of Ft. Worth.

I got a new OPS (under warranty) and the gauge is back to normal, but the lift pump still runs all the time when plugged into the relay.
 
I don't know. When the lift pump is unplugged, everything works as it should. There is a red LED on the relay that comes on when there is power to the lift pump.

Lift pump plugged in---always on
Lift pump unplugged---works as advertised, meaning lift pump power for prime, while running, and whenever you press the overide button. Off with key.
 
Sorry, when I say "lift pump unplugged" I mean the red led on the relay (which glows when power is on to LP) comes on when it is supposed to (as advertised). When I plug in the lift pump, the red led as well as the LP are always running.
 
Yeah, tough to call as I am not familiar with JK's setup. I build my own. I relay should be easy enough to test. Otherwise call JK. Shoot him an email. he checks them after hours sometimes.
 
U got electric going to the lift pump from two sources. If the red indicator lite works correctly with the LP unpluged and then u plug it up and it runs with the switch off there is electricity coming from somewhere. R u sure the relay is wired correctly? Did u by chance touch the relay poles together with the connectors while installing them? I did this and fried part of my OPS relay and had to get another relay.
 
4thesporty said:
Then the relay is wired to switched 12V and the + side of the battery.

In the process of doing all this I must have fried my original OPS as my oil pressure gauge is now reading all the way to the right.
Click to expand...

This relay, are the contacts numbered 85,86,87,87a and 30 and what do you have plugged into each? It sounds like something is wired funky, can you post the install instructions, is there a diagram?

What happens with the stock LP connector?
 
It happened to me when I installed mine. Turned out my LP was bad.

The harness works as intended after I replaced the LP.

I put the fuse tap in the F-SOL fuse. No matter what I did, it keeps turning on till LP was replaced.
 
That doesnt sound good, if a "bad" lift pump could make the control box run continuously, could drain your battery, if you didnt notice.

That control box has logic circuits in it, not like a normal relay. I dont understand how that happens still.
 
Yeah the directions are a bit confusion. In the first pic it looks like you just plug into the existing OPS but the second sheet looks like your t'ing off to a separate OPS soley for the LP. Thing I don't like about this setup from what i see is if the relay box takes a dump your screwed where as if you build your own using a standard relay you can jump it in an emergency or pick one up at any Auto Parts store.
 
I talked to JK, he suggested all the checking by plugging and unplugging cables.
Move the fuse tap around, etc. Nothing solved the problem.

So I plugged the old cable in there. A few weeks later, I found out that my LP was bad.
I was new, so I have not learned how to test, etc. At that time, I learned.
The LP was intermittently working. After replacement, I plugged in the new harness.
Walla, it worked. JK have no way of knowing that my LP is bad.

I should have noticed the sign of LP failing.
 
Glad to see that you figured out the issue, and Kennedy took care of the lift pump. :thumbsup: I have the double setup on my Duramax.
 
Aces,

Actually, you can leave the factory lift pump connectors in place and not use them as the fatory system remains untouched save for the tee in the OPS port. So, should this relay ever fail, I can unplug the lift pump from it, and plug it into the factory connector still.

JMJ,

My LP has no signs of being bad right now, however I have not checked pressure yet, but I'm glad you figured it out. I am talking with JK now over email and will report back what I find out.
 
And again I state.....the first and most valuable mod to make is a fuel pressure gauge followed by OPS relay and LP primer button mod!!!! GM really missed it not putting one in and I notice so many people that have put in gauges to monitor their "tuned" turbo but still have no idea what their LP or filter is doing since they have no pressure gauge for it.
 
Fuel gauge is on my list of stuff to do after I get this figured out and my bum EGT guage working. (autometer wants me to send gauge and probe back to them for testing)

In conversation with Kennedy, he suspects the only thing that could be happening is ground leaking internally in the LP. So, i'm shopping around for LPs now!

I figure if i'm going to spend ~$80 on a stock one, why not buy something a little better with a smaller chance of failing soon.

Any suggestions?
 
4thesporty said:
Fuel gauge is on my list of stuff to do after I get this figured out and my bum EGT guage working. (autometer wants me to send gauge and probe back to them for testing)

In conversation with Kennedy, he suspects the only thing that could be happening is ground leaking internally in the LP. So, i'm shopping around for LPs now!

I figure if i'm going to spend ~$80 on a stock one, why not buy something a little better with a smaller chance of failing soon.

Any suggestions?
Click to expand...

A Walbro from PMDCable, mine is on the way! :thumbsup:
 
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