To switch the GP's I cut the small red wire on top and run the switch wire inside the cab, correct?
I got a little confused yesterday, I had both wires totally disconnected and when I turned the key to ON the wait to start light came on and the amp gauge still dropped as usual (like GP's were still on.

 

Whichever wire that goes to the PCM is the one you splice IIRC.
Then throw a relay in the middle.

Going from memory.

Was tempted to do this long ago, just never got around to it. To many other projects.

 

If you want to disable the GPR you can use either small wire to go to the switch and back, probably best to use the purple wire though. Red wire is hot all the time, from fuse #22 and purple wire is pulled to ground by the PCM to activate the relay. WTS light will always come on regardless because it is a different circuit in the PCM. Don't understand why AMP gauge doing what you are describing (both wires disconnected, or even 1) unless the GPR is shorted internally and a test light or voltmeter will troubleshoot that.

 

Thanks for the reply's I'll use the purple wire for switch and do some testing on the GPR.

 

If that doesn't work for you Rich I can look at mine and see how I did it and report back. I can't recall now because of gray matter. lol After the first start of the day I flip mine off. It just bugs me to see them run all the time when I just do short trips.

 

i heard you can run the towo littler wires to a switch in the cab and when you hit the switch they come on????

 

You just need to run the purple wire into the cab. The PCM grounds the purple wire to turn the GPR on so if you ground that wire through a switch you can turn them on yourself, or if you want to disable them all together you just break that wire's path back to the PCM so the PCM cannot take the wire to ground.

 

You can also take the purple wire off and run a fused wire from battery to a toggle then to the relay post the purple wire came off of. Maybe i miss under stood your question though. This Method bypass the pcm.

 

The unasked/unanswered question is - does the OP want to override the PCM and turn them OFF (when the PCM wants them on), or override the PCM and turn them ON (when the PCM wants them off)? If the former, then s/he'll need to interrupt (cut) the purple wire on the relay and put a switch in SERIES. Switch open -> GPs off. If it's the latter, s/he'll need to put a wire on the purple wire terminal, and run it to a switch that switches to ground, so it acts in PARALLEL with the PCM. If s/he wants both, then a three-position switch, incorporating both of the above, is in order.

 

OK: I just want to be able to manually turn on the glow plugs when I want or need them on. I think I will save some wear & tear on the electrical system. The GP's & Stancore Relay were new last fall. I have purchased a momentary switch that will return to off when not holding it in the on position.
I was testing things a little today and found that if I grounded the purple wire the GP's were off, but there was still more current draw on the amp gauge than I expected. Also if I need to fuse it what size fuse should I use?

 

Only if you intend to run the wire to the negative side of the battery. The Red wire is hot all the time as was stated above (hussler) and the PCM take the purple wire TO GROUND to engage the GPR.

This is what the OP wants to do according to his reply below.

No fuse is needed as the wire you are running is a Ground and the positive coil wire is already fused. So take two wires from your momentary switch, attach one to the terminal of the GPR where the purple wire formerly was attached (take the purple wire off the GPR) and attach the other wire from the switch to a good ground. Just tape off the purple wire good and tie it back out of the way (or leave it dangling there somewhere). Press the momentary switch (grounding the negative coil terminal of the GPR) and the GPR turns on the GP's. Smile, and consider for a moment how much better a job you do of glow plug management than the PCM does.

 

One comment: as mentioned, both of them work, but if you use the red wire (hot) it lets the PCM turn off the glow plugs if you leave them on.

The way with the purple wire (ground), you have total control over the glow plugs and as long as the switch is on the glow plugs are activated. If you leave the switch on for two hours the glow plugs are on for two hours.

So, pick the one that is best for you. As I dont trust in my memory I use the hot wire.

 

Yes but breaking the hot (red) wire only enables you to turn OFF the GP's when the PCM is calling for them to be ON. Using the purple wire and a momentary switch (only stays on as long as you keep pushing it to the on position and returns to off as soon as you let go) you can turn them on and off any time you wish and they stay off any time you aren't pushing the button.

 

I don't trust my memory much anymore either (to much gray matter) that's why I'll go with the momentary switch,
I'll let ya all know how it works when get it done.
Many thanks to all that replied.

 

Richdawg, if possible take some pics and write it up. I would like to see it for sure.