Looking for manual glow plug experts

8769bigred

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I’m trying to figure out how the manual glow plugs on my truck work. I did not install this system but it has worked amazing for the last 7 years since I have owned the truck.

There is a push button in the cab. When you hit the button the glow plugs run and then after a while the added solenoid begins to rapidly cycle. When that happens you stop, and start the truck.

I’m pretty sure this peice connecting battery hot via the factory glow plug solenoid is a thermal trip breaker. It says it’s rated at 40 amps. I think this is what gives the ‘automatic’ shut off signal to the driver

(the solenoid clicking repeatedly is the signal)

There is one other wire I don’t understand the purpose of. It sends power to the small white and orange wire at the glow plug controller connector. This wire according to my meter is the main power wire. I’m not sure how the signal is getting to the purple wire on the factory solenoid to open up big power to the plugs. Has any one seen this system?
 

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DirtyWood

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What the bleep?!
I've done a couple manual conversions but not like in those pics. That wiring job is begging to be redone. I would try and ditch as much of that glow plug wiring as you can and start fresh. I got my initial info from here, https://www.oilburners.net/articles/glowplugbypass.htm

Since you're going manual I would look into the White-Rodgers relay, https://dieselorings.com/products/16-009-white-rodgers-stancor-586-902-monster-glow-plug-relay

On one truck I kept the factory wires that supplied power to the glow plug relay but on the other I ran fused 2 gauge as the power feed to the GP relay. It's so easy to redo the glow plug wiring as an all new stand alone system that it seems worth it in my opinion.
 

8769bigred

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@DirtyWood nice info thanks you very much!

I have done several manual conversions on other trucks but never like this. I really like the ‘timer’ feature this system has built into and it would be neat to replicate. Before I rip it apart I was hoping to figure out how it actually worked and maybe retain the automatic timer feature.
 

franklin2

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A regular "timer" is not really a very good feature to have. If you want something automated, it needs to be tied to the temperature of the engine. A colder engine needs to cycle the plugs longer. The easiest and simplest circuit is just a straight voltage to your glowplug relay, and "you" are the timer. A very cold morning you need to hold the button longer or just cycle while counting to 10 for a cold morning, and if it doesn't take off, cycle it again manually. That is what manual means, everything is simple and manual.
 

89Laredo

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Need more pics. Where is that solenoid getting its power and signal from? Im wondering if they are using the factory GPC as the timer to control the aftermarket solenoid. But I could be wrong since my 6.9 was converted to 7.3 controller a long time ago and Im not exactly sure how the older style works.

With how easy it is to burn out these plugs Ive never understood the obsession with manual control. I did it for a little while and burned out a set of plugs so went back to the 7.3 controller. I guess it would be fine with self regulating plugs but it seems like no one goes that far.

IMO I would delete all that crap and swap to a 7.3 controller and if you are super paranoid you could also put that on a switch.
 

OlKoot

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Simple is better. Use a wire attached to a glow plug and watch it get red hot, time how many seconds it takes to get red/orange. May be 6 seconds, may be 10.. also a good way to test if the work still. Then use a relay (HD grade solenoid) to power them all at once so they get direct battery power once your button is pushed.. dash mounted button needs only a 14 gauge wire, glow plugs 10 g... And never look back.. constant duty seleloind works the best. Wich glow plug you use , may be good to 15 seconds or only 10. All you need to start.
 

Grumpy bruce

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Had trouble a few years ago with factory set up. Middle of no were ,jumped the controller with remote starter and she fired right up.when I got home I rewired for manual push button, count about ten seconds ,starts right up. Got info on this site on how to do it
 
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