rewire lift pump power

[Shad]

I would like to start my lift pump before and while my truck is starting. Which wire and location could I use my glow cycle to start my lift pump? I noticed the 96 and up already do this. I thought this would be a good time to do this when I install my remote starter.

[HowieE]

If you pick up voltage on the output side of the glow plug relay and connect that to a relay coil and then ground the other side of the realy coil you will have a switch that is on whenever the plow plug circuit is hot.
Wire the normaly open contact and the common contact of the realy across the oil switch, gray wire and orange wire. The orange wire on the oil switch is hot at all times and thus when your remote calls for the glow plugs it will also close the relay and call for the lift pump. Once the truck starts the factory oil switch contacts will keep the pump going and the relay will drop out as soon as the glow plug circuit shuts down.
Bulldog may already have addressed this point since a GM diesel need the lift pump running before attempting to start. If not they sell the relays seperatly.

[HowieE]

Please do not confuse my discription above with the "Oil Switch Mode" that is highly recomended to protect the oil switch. The only differance is were you pick up the source voltage for the relay coil. For the remote you pick it up on the output of the glow plug relay and for the oil switch mode you pick it, and the common conection of the relay, up from the orange wire on the oil switch.

[Shad]

I have an extra relay from my last install I should be able to do this with that. and that should solve the lift pump problems.Thanks for the reply, I'll let ya'll know how it goes.

[Shad]

Does anyone have the wire diagram to to the relay upgrade mod? I thought I saw that in the members area at one time. When I find time I would like to do this mod. I am finding that if I run the lift pump before the truck starts it runs much better.

[HowieE]

I thought I had discribed the oil switch mode above but in reviewing it what I discribed would reduce the load on the oil switch contacts but not completely bypass it.

To completely remove the lift pump current off the oil switch do the following. Cut the white wire coming off the oil switch and attach the piece coming from the oil switch to one side of your relay coil. Ground the other side of the coil. The other piece of white wire goes to the common contact of your relay. The normaly open contact goes to the orange wire on the oil switch.

Wired this way the oil switch current will only be that of the relay coil and should last forever. The relay will close when the oil switch sees pressure and carry the current of the lift pump. Small relay contacts are generaly rated 30 at amps, more than enough for the lift pump load.

[Shad]

Thanks again. I'll be working on this project in about 2 weeks. I will be helping my dad with setting his new house next 2 weekends. so I'll post then after I complete the job

[Shad]

I finally got the pump wired to come on with the glow cycle using a 30 amp relay today. Thanks to you guys and a little help with my helm manual I was able to find the wires. I hope this helps my remote starter do its job. I will try in the morning and see how it works out, The remote starter was trying 2-3 times before starting. Hopefully 1st time in the morning.

[Shad]

It started 1st time!!! I pushed the remote start button this morning and fired right up at 15 deg. not plugged in..Thanks again!