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Discussion Starter #1 (Edited by Moderator)
Installed Leroy's Diesel lift pump harness on my 92 6.5. It has the wait to start wire. Now the lift pump doesn't run when the engine is running, only when the glow plugs are energized. put in a new OPS ,didn't help. Haven't heard back from Leroy yet, but it's the weekend. Any ideas?
 

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Installed Leroy's Diesel lift pump harness on my 92 6.5. It has the wait to start wire. Now the lift pump doesn't run when the engine is running, only when the glow plugs are energized. put in a new OPS ,didn't help. Haven't heard back from Leroy yet, but it's the weekend. Any ideas?
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Did you install an AC Delco brand replacement OPS??
If not, aftermarket electrical parts bring the gremlins out in a 6.5L
 
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Discussion Starter #3
Yes, ACdelco replacement
 

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Reversed connector?
 

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Check the LP fuse on the firewall.
Does the LP run while cranking the engine, that is what the OEM relay does.
 
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Is there year specific instructions for this kit? I could imagine 91-93 being one thing then 94 being its own as well as 95. Maybe just a different color wire or something simple like that?


Did the lift pump work correctly before you did this mod?
 

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Discussion Starter #7
yes different kits for 92-95,96 and up. not sure if the pump was working before, I replaced the lift pump and OPS (both AC delco) just for preventative maintenance.
 

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Discussion Starter #8
With this harness, when the key is on one click to activate the glow plugs, the lift pump comes on to "prime " the injector pump which it does, the problem is once the engine is started and the glo plugs go off the pump shuts off
 

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Discussion Starter #9
checked fuse on firewall, it's good, is there more than one on the firewall?
 

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Just the one. Unplug the OPS conn and short the ORN wire to the GRY wire, LP should run. ORN wire is BATT voltage so be careful.
 

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Discussion Starter #12
Yes, he said it sounds like a fuse or relay problem. I checked the fuse in his harness and it's good, checked the fuse on the firewall, good also. Not sure there is a relay in original lift pump harness??
 

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Is it an electrical or mechanical LP? Just making sure.
Did you try to reverse the connector?
 

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Discussion Starter #14
Rechecked fuse on firewall, it was good but noticed the fuse was very loose in the holder. I replaced the holder and fuse and that did the trick! Lift pump now runs as it should.(thanks Glagulator for the tip) thanks to all for their ideas.
 
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