Lift pump test wire on 96 up

[sturgeon-phish]

After some searching, a 9-15-04 post spoke of an open connector in a bunch of wires by the driver's side hood hinge, where you can apply 12V, and the lift pump should run. I'm trying to find it because I think my lift pump has gone south. It no longer clicks during the wait to start cycle, but I think it is working when the motor is running. For a while after rapping the lift pump it would click, but that does not work now. Sometimes the pump will click very slowly at wait to start, but not often.
I want to find the connector to see if my lift pump is bad or if it is the OPS. Off on vacation for two weeks so I have the time to fix what is broke!
Thanks
Jim

[ucdavis]

My rig is different than yours in layout but not totally. Mine is a female spade connector right next to the "fuel relay", which on your rig should be on the firewall above & to the driver's side of the 15 pin connector (which is near the center rear of the engine). That'd put it somewhere above & near the OPS.
If you think you have an OEM OPS, then it is bad. The early OPS's were poorly designed & died after not too many cycles, relative to what you'd expect from overall diesel design.

[CareyWeber]

Originally posted by Jim Sturgeon:
After some searching, a 9-15-04 post spoke of an open connector in a bunch of wires by the driver's side hood hinge, where you can apply 12V, and the lift pump should run. I'm trying to find it because I think my lift pump has gone south. It no longer clicks during the wait to start cycle, but I think it is working when the motor is running. For a while after rapping the lift pump it would click, but that does not work now. Sometimes the pump will click very slowly at wait to start, but not often.
I want to find the connector to see if my lift pump is bad or if it is the OPS. Off on vacation for two weeks so I have the time to fix what is broke!
Thanks
Jim Jim,

It's a red wire apply 12volts to it the lift pump will run if it works.

If you are looking at the engine relay center from the drivers side it's by the upper right conner of the relay center.

Carey

[sturgeon-phish]

I appreciate your reply and your patience with the 6.5 diesel inept, but when I look at the relay center, there are a lot of red wires, smaller gauge and different colored wires twards the passenger side and larger gauge, mostly red wires, twards the driver's (fender) side, with no open connecter as I can find. I do see a large gauge red wire attached to the lug marked AUX B. Am I looking in the right spot for the connecter, or am I still lost? I may be telling on myself but I searched for several minutes before I found the OPS. :rolleyes:
Thanks again and MERRY CHRISTMAS!!! smile.gif
Jim

[CareyWeber]

Originally posted by Jim Sturgeon:
I appreciate your reply and your patience with the 6.5 diesel inept, but when I look at the relay center, there are a lot of red wires, smaller gauge and different colored wires twards the passenger side and larger gauge, mostly red wires, twards the driver's (fender) side, with no open connecter as I can find. I do see a large gauge red wire attached to the lug marked AUX B. Am I looking in the right spot for the connecter, or am I still lost? I may be telling on myself but I searched for several minutes before I found the OPS. :rolleyes:
Thanks again and MERRY CHRISTMAS!!! smile.gif
Jim Jim,

The wire is in the bundle the comes out just under the aux B terminal and goes towards the firewall. The wire has a female spade connector on it, and the wire is only about 6" long measured from the relay center.

Carey

[jjgmc96]

mine was taped up in the bundle just behind andto the left of the brake boster. i wired to switch so i can test it and prime filter.

[sturgeon-phish]

Good news / bad news. Found the terminal smile.gif , when 12V applied, nothing :( no click, no hum, zip. So, lift pump replacement time, right?

Guys, thanks for the help, the connector was exactly where you said it would be, if it had been a snake I'd be bit.
Jim

[rjwest]

Maybe..... on 96 and latter the
wire goes through a Normally closed circuit of the relay to the lift pump....( if you want a copy of circuit, send me email address. ( qwestav@attglobal.net)

Need to check if voltage is at lift pump,
After connector, when jumper is attached to 12v.


I use a straight pin through the wire at the lift pump ( after connector ).


1 pin through each wire, should get 12 volts..
accross voltmeter. if so, pump is bad.
( this checks voltage and ground )

if not, need to trace back to relay.or ground..

[sturgeon-phish]

Checked voltage at lift pump while applying 12V to spade connector and I saw 12V at lift pump. Replacing lift pump Monday. I'll let you know how it tuns out. Thanks again
Jim

[sturgeon-phish]

Replaced lift pump with a NAPA unit ($75) and I can hear the pump at start-up again! Truck seems to accelerate a lot better now. Thanks for the help.
Jim

[sturgeon-phish]

I disected the lift pump to see if I could determine the cause of the failure. I did not see any dirt gum or other contaminantes, but I did see what appears to be a cpacitor that has blown.
http://img26.exs.cx/img26/7470/1000046resize9ld.jpg

http://img26.exs.cx/img26/2715/1000047resize3lv.jpg