Just to make sure I understand what I think I know already. If, and I did, when I jumper the fuel pump relay the lift pump runs and IF the truck dies when the petcock is open and the truck is running with the relay installed, and IF the lift pump was replaced 3 months ago, then I got a bad OPS. I got that right???


hope this stops it from trying to buck me off once or twice a day.

Just wire it like TDG says with an IGN. wire to the GREY wire off the OPS connector.

and that does what run with the key on ?


I was going to replace the OPS or put a relay in but I can't find the diagrams for the relay this morning


Edited by: bowtie

Yeah,


The lift pump will run with the key in the "On" position. You don't have to replace the OPS to make this work. You run a wire from your fuse box you know is only hot with the key on and splice it into the grey wire from the OPS connector. Problem solved.

Yeah,


The lift pump will run with the key in the "On" position. You don't have to replace the OPS to make this work. You run a wire from your fuse box you know is only hot with the key on and splice it into the grey wire from the OPS connector. Problem solved.





Great, But why couldn't I jumper cross where the fuel pump relay plugs in. isn't it also powered with the key or would the pump run without the key on if i did that?

The fuel pump relay is powered when the glow plugs are on. The OPS takes over when the motor starts. An ign. wire would be a better power source. if you still want to wire a relay switched by a new OPS, I can help with that too.

The fuel pump relay is powered when the glow plugs are on. The OPS takes over when the motor starts. An ign. wire would be a better power source. if you still want to wire a relay switched by a new OPS, I can help with that too.


Thanks qm i was concerned about the always on fuel pump but I've run them like that for years myself so thats no problem now. I stopped by my friendly parts plus store this morning just to see what might be there I needed for anything. I found a "Add-A-Circuit" from littlefuse that was just the ticket for this problem. It allows you to add a circuit by "piggybacking" to another fuse and still protect the new circuit with a different. I plugged in to the under hood fuse box and piggybacked from there to the number 30 pin where the fuel pump relay plug in (relay removed oh course), and wow the fuel pump runs with the key on and off with the key off. No long wiring and it has it on fuse all to it's self. I like'd it and thought I'd pass it along to everyone.


Edited by: bowtie

WOW been driving around all day after installing this add a circuit and haven't been bucked once. In fact the engine runs smoother and pulls better all the way up to 3200, where as before it wouldn't pull much past 2750 and then would start to bucking like it was running out of fuel, which I guess it was so to speak. Anyway hope this helps someone else ou there as a quick and easy way to bypass the ops and keep everything nice and clean install.