I was wondering if any one has tried to come up with a switch to control the glow plugs. I know you guys have come up with a GPR led mod. How hard do you guys think that it would be. And do you guys think this could be a helpful mod?

 

I dont see where it would be hard since the relay is right on top of the motor. Just have to figure out which leg is what on the relay. Dont know what advantages it would give you. I hadnt done the LED mod and havent looked into it.

 

I guess you would basically just supply power to the in side via a switch instead of from the factory wiring.

 

Dan has done it. Maybe he wil chime in.

 

The Glow Plug Relay is looking for a ground from the PCM to light the glow plugs. If you remove the wire that comes from the PCM on the GPR (insulate it), you can then run a wire to a momentary switch and on to ground to have manual activation.

In warm climates, this is a very good idea, as we virtually don't need glow plugs where I live (at least MOST of the year)!

I wrote something about this a little over three years ago:
https://www.ford-trucks.com/forums/4...ml#post3102511

Pop

 

I installed an LED on mine and also a manual switch. A switch on the dash to control the coil between 85 and 86, and a fused hot wire to 87 and a lead from 30 to the control B+ pole of the GPR.

This setup is the best of both worlds in my opinion. It allows me to turn the GP's on without the key in the ignition, but the PCM will still shut them off after the 2 minute or so cycle (even with no key in) to keep me from accidentally running the plugs too long.

I can't tell you the "why" the PCM can still control off-time without looking at a diagram- I can tomorrow if you like. To get full manual control, you must remove and isolate the factory B+ control wire to the GPR coil.

 

The reason is because the PCM still supplies the (likely open-collector) ground to the GPR, but I really wonder how it can do that without the key on.

Pop

 

Thanks natewoz, Marv, Nic and Lee. Being able to turn on the glow plugs with out turning on the key would be very handy. Especially with me driving the diesel to school.

 

That would be very nice to leave them on as long as you wanted. So your dad is going to let you drive the truck to School?

 

That's a pair of dead batteries that hasn't happened yet.

Pop

 

Yup he is letting me drive to school as long as my grades are good and I am in wrestling.

 

Interesting idea, I always like having more control. I am just not sure how much benefit it would create...

 

Manual control of the glow plugs offers you the benefits of running the glow plugs for a longer period in REALLY cold weather, and not having them AT ALL when it's the middle of the summer and a hundred degrees out.

Think of all the battery current you'll save from being used. WIthout the GPs running, the starter will have both batteries all to itself, and the truck may even start quicker!

Pop

 

If you do this I would definatly do the LED mod. Or like Pop saod you'll be looking at a pair of dead batteries. The current that your glow plugs draw will suprise you.

 

Thats a good point Jim. How much would and led like the one to be used cost?