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Manual Glow Plug Override How-To

IIRC, won't the PCM set a code if it knows that the glow plugs are on when being used with the factory glow controller? Seems that I remember that it would set code, as if the controller had failed and was keeping the glow plugs on.
 
chevydiesel said:
IIRC, won't the PCM set a code if it knows that the glow plugs are on when being used with the factory glow controller? Seems that I remember that it would set code, as if the controller had failed and was keeping the glow plugs on.
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I don't think so...

But in this "mod" you aren't "using" the factory glow controller. You are jumping it. On 1996 and earlier models the glow plug light came on if the glows had power, on 1997+ the glow light is controlled by the PCM. The PCM iirc only controls the glow plug controller, it doesn't get any feedback from it. But its been a while since I've looked at the glow system diagram.
 
If anyone wants to do a glow plug mod like this and needs a switch I can probably find one. I just got 2 of them from a surplus store near by. They had a square switch for $2and a round button for $4.
 
I can't remember how much I purchased my switch for but I bought mine at Tractor Supply Co. and it almost looks OEM lol

switchlocation-1.jpg
 
That's a good-lookin' switch! I like the fast-idle pair that Justin installed, too. Haven't found any of those up here, either.
 
I like that switch greenmachine, looks stock. Heres the switches I got. The black switch would probably look good. The new truck I got the guy had 3 switches all cobbled together under the headlight switch.
 

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what about running 1 switch with momentary on one side and ON on the other (dead in the middle of course) with the momentary on the glows and high idle on the other side?
 
That would work. I used 2 red lighted on/off switchs side/by/side. Easy to see, and red gets your attention so's not to leave it on.
 
Im working on this right now, Im just using the puch button I have in the picture. The last owner had 3 switches under the headlight switch. Im going to take 2 of them out. One was for lights on the front bumper, another for a ooga horn, and the other to turn on a light in the boost gauge.
 
540s10 said:
what about running 1 switch with momentary on one side and ON on the other (dead in the middle of course) with the momentary on the glows and high idle on the other side?
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Do they make switches like that?

Anyways, that "would" work if they do make switches like that, but your truck is a '97 and you can have two separate switches since you can have 3 different high idle settings. If you want all three different high idle settings why not just use two switches for high idle and one momentary switch for the glows? Just wondering, there's plenty of room for switches on the dash.

Soon I will have three switches, High Idle, Glows, TCC Lockup ):h.
 
Green Machine said:
Do they make switches like that?

Anyways, that "would" work if they do make switches like that, but your truck is a '97 and you can have two separate switches since you can have 3 different high idle settings. If you want all three different high idle settings why not just use two switches for high idle and one momentary switch for the glows? Just wondering, there's plenty of room for switches on the dash.

Soon I will have three switches, High Idle, Glows, TCC Lockup ):h.
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yea i looked last night and can get the switch. I Know i could have that many idle settings, but I really don't think I would ever use them all unless i was trying to impress my friends or scare my neighbors.
 
Here is mine, I had everything laying around but the switch.
 

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I've seen someone using a Painless Wiring, lighted, momentary/off/constant switch in another application. Here's a link to the switch the guy was using -

http://www.summitracing.com/parts/PRF-80402/

My manual glow extension was done by the method authored by RJ Schoolcraft, shown in The Diesel Page/Jim Bigley's 6.5L Turbo Diesel Volume II. It basically uses a momentary switch & a couple of diodes, to activate the original glow plug controller/relay on the '94 & '95 6.5 trucks.

I used a common push button starter switch available at most O'Reilly Auto & Advance Auto parts stores. It's silver, pics of the dash switches/gauges are in my album. I do like the flat black color of Green Machine's switch a bit better - more low key blending in w/ the dash color better.

As mentioned previously in this thread, the diodes are to prevent voltage feedback to the PCM.

This setup hasn't set any DTC's for me; don't know if it would if one tried after-start glow for too long a time?

My guess is the PCM doesn't "see" any pre-start/ign key off glow time. It can see any manual after (start) glow time (confirmed by the GMTDScan Tech glow voltage & glow feedback voltages). I think this system utilizing the factory glow controller/relay is a relatively simple & cost-effective way to get manual glow control.

You tap into a yellow wire near where it plugs into the PCM. I mention this in case anyone decideds to go w/ this method. There happen to be 2 yellow wires of similar gauge on that loom/plug to the PCM. They're directly across from one another. The "other" yellow wire goes to the CPS. It's easy to mistakenly choose the wrong yellow wire, so follow the instructions carefully.

FWIW - I took the truck to IA last weekend. With all the starting system enhancements, & Bosch Duraterms manually glowed for 12 seconds before letting the Kennedy chip'd PCM do it's glow cycle, the 19:1 engine started after an overnight low of -2 F. I only tried it once, simply to see if it would. No doubt hard on things & it got the block heater(s) plugged in for the next night's -8 F start. Not saying OEM compression wouldn't enhance starting; just providing a data point that lower compression starting defficiencies can be dealt w/.

That said, it took a fair bit of grille/cardboard, airflow limiting experimenting to find a balance that would allow engine oil temps warm enough to suit me. 195 coolant thermostats easily upheld coolant temps, but at -8 F outdoor temp, the big 48-plate oil cooler & remote filters setup wouldn't let oil temps climb above 145 degrees until the grill airflow was largely blocked off, so mostly just bumper nostril airflow left.
 
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Hi I tried using the same setup but for some reason my glowplug light wont go on but I have power to the solenoid because I can hear it click when I flip my switch just wondering what the problem might be?
 
Welcome to TTS Jason

The light works normally otherwise? If so I can't think of why it doesn't come on if it is done correctly.
 
Have to put a meter on it and ensure it is sending the power. Crack in the solenoid is probably the death nail however.
 
An old Ford starter solenoid will work, or being in Canada, Princess Auto has ones that will work.
 
It wasn't the crack in the solenoid I replaced it with a new one but the same outcome I will put a meter on it and see. what kind of voltage should be going through.
 
Also is there a chance since my truck is a 98 would the glowplugs be on when I turn my switch and the light not come on because the ecm doesn't recognize that the glowplugs are on.
 
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