• Welcome to The Truck Stop! We see you haven't REGISTERED yet.

    Your truck knowledge is missing!
    • Registration is FREE , all we need is your birthday and email. (We don't share ANY data with ANYONE)
    • We have tons of knowledge here for your diesel truck!
    • Post your own topics and reply to existing threads to help others out!
    • NO ADS! The site is fully functional and ad free!
    CLICK HERE TO REGISTER!

    Problems registering? Click here to contact us!

    Already registered, but need a PASSWORD RESET? CLICK HERE TO RESET YOUR PASSWORD!

Manual Glow Plug Override How-To

chrisk1500

New Member
Messages
875
Reaction score
0
Here is a quick 'how-to' on installing a manual glow plug override.

The purpose of the override is to jump the existing glow plug controller on the truck with a solenoid. You NEED to have self-limiting plugs in order to perform this mod safely. Self-limiting plugs include AC Delco 60Gs and Bosch Duraterms.

For this mod you will need the following:

16 gauge wire
- 15 feet would be TONS of wire
8 gauge wire - 6 feet would be lots of wire
various wire connector ends - depending on what you use you will need a selection of eyelets, shovels, or spades.
Ford starter solenoid - I picked one up at a parts place for about $10. Tell them it is for a 79 F100.
Switch - I used a lighted bat handle SPST switch. YOU are free to use a push button style momentary switch if you are concerned about accidently leaving the switch turned on and running your batteries down.
Add a Fuse - I just jammed the 12v lead wire into the switched side of the radio fuse, but putting in an add a fuse would be the cleanest way to get power.


Step 1 - Find a place to mount your switch. On my 95, I pulled out the center bezel and put it there. Drill a hole for the switch. (PIC 1 - mounting, PIC 2 - Switch)

Step 2 - Run the 16 gauge wires. You will need 3 wires. One runs from a ground to the switch. One runs from a 12V source to the switch. One runs from the switch to the engine bay where it will be hooked up to the solenoid.
(PIC 3 - Wires hooked up to switch, PIC 4 - 12V source at the 'Radio' fuse)

Step 3 - Put the interior of the truck back together by reinstalling the bezel(s).

Step 4 - Find a place to mount the solenoid. I mounted mine on the firewall beside my alarm siren. (PIC 5 - Solenoid mounted on firewall)


I have exceeded my upload limit for this post (and I am not done the install anyways - it got too dark outside too quickly).

In my next post I will show you how to hook the solenoid up to the glow plug controller...
 

Attachments

  • bezel.jpg
    bezel.jpg
    35.1 KB · Views: 142
  • switch.jpg
    switch.jpg
    36.8 KB · Views: 145
  • switch-installed.jpg
    switch-installed.jpg
    31 KB · Views: 151
  • wire-tap.jpg
    wire-tap.jpg
    38.6 KB · Views: 161
  • solenoid.jpg
    solenoid.jpg
    42.8 KB · Views: 229
....continued....

Step 5 - Locate the GP controller at the back of the engine. Take off the boots covering the nuts that hold the power supply and the glow plug harness to the controller. (PIC 1 - GP controller circled in white, PIC 2 - GP controller with boot and wires disconnected)

Step 6 - Measure how much 6 gauge wire you will need to make your connections from the GP controller to the solenoid you have mounted on the firewall. Crimp on the eyelets to both ends of each wire. (PIC 3 - wire ready for install)

Step 7 - Connect one of your wires from one side of the GP controller to one side of your solenoid. Connect the other wire from the other side of the GP controller to the other side of the solenoid. Reinstall the power supply and GP wires to the sides of the controller that you took them off of. Connect the 16 gauge wire from your switch in the cab to the 'S' terminal on your solenoid. (PIC 4 - wires connected to the controller, PIC 5 - wires connected to the solenoid)

Now your install is complete. Since you tapped into the 'radio' fuse, the GP override will not work unless the ignition is turned to the 'on' position. This in itself is a safety feature because it will not be possible to accidently leave the override turned on overnight.

To use this override, get into your cold truck and turn the ign on. Let the glows go through their normal cycle. Once the glow plug light turns off, turn on your override switch. The GP light will come on again and your glow plugs will heat up. As long as the GP light is on on your dash, your GPs are getting power. Once you are satisfied you have had enough glow time, turn the switch off and proceed to start the truck.

My typical cold start cycle is letting the GPs go through their own cycle and then overriding the plugs for another 10 seconds or so. This results in a super clean start. Once the truck is running, the PCM will run the programmed after glow cycle to keep the engine running clean.
 

Attachments

  • controller-connected.jpg
    controller-connected.jpg
    44 KB · Views: 192
  • wire-ready.jpg
    wire-ready.jpg
    45.4 KB · Views: 155
  • controller-ready.jpg
    controller-ready.jpg
    36.8 KB · Views: 172
  • controller1.jpg
    controller1.jpg
    37.2 KB · Views: 190
  • solenoid-done.jpg
    solenoid-done.jpg
    37.3 KB · Views: 208
Last edited:
Already done!!

Another great write up for the sticky's I think. nice job chrisk1500

It's already been enshrined in the Technical Library!

Attaboy, Chris! As usual, a nice clean job, great write-up, and good pics... can't do better for a DIY 'How-to'... even old guys can follow this!

I think we'll keep you around... :D

Jim
 
Last edited:
Does anyone in Canada have any other suggestions/part numbers as to which solenoid one can use for the glow plug mod. I was at Princess Auto today to get the solenoid that I was told about, but apparently PA discontinued carrying them. Looks like I was a little late on that $8 deal.
 
Does anyone in Canada have any other suggestions/part numbers as to which solenoid one can use for the glow plug mod. I was at Princess Auto today to get the solenoid that I was told about, but apparently PA discontinued carrying them. Looks like I was a little late on that $8 deal.

Got an auto wrecker near you? Or maybe check a Ford dealer for the price of a new one.
 
Relay is a relay so long as it is up to current amperage draw, as indicated on the relay, got several good candidates under hood of the 6.5 in the fuse center there,

Chris not to steal the thunder from this very good post; and more of a question to tron techs out there; since the high current draw is still being carried by the glow controller, do you even need a relay, one of you tron techs out there do the tron math, but wouldn't a momentary switch to pull in the contact of the glow relay do the same thing, PCM or glow realy during start cycle can't be applying much current to that, & I'm thinking a good momentary switch would hold the current for a pre glow. Since PCM is involved does there need to be diode protection so you don't backfeed when doing a pre glow exercise and zap PCM or is underhood relay protect the PCM sufficiently.

I'm away from my manuals/schematics so I'm just brain storming.

Chris do you have a meter you can get current draw readings with, that way we know how much current is in the control side you are energizing, as I'm guessing if long extended glow may require a solenoid to be used vs switch alone, but even a riding mower starter relay would be sufficient and easy to find, I'm guessing amperage is 1amp at most, tron techs your opinions please
 
Last edited:
TD - I am not an electrician by any means....

I have a run of the mill digital multimeter. If that will test what you are looking for, then tell me how to set it and where to test and I will give you numbers...

The reason I used the solenoid was so that I would not have to cut and splice into the OEM harness. I try to keep splices to a minimum in order to make troubleshooting future electrical issues easier.
 
On the controller there should be a Yellow wire to the relay and some big Orange ones.
You need the Yellow. Disconnect it. Put the meter on the highest AMP scale that it has and put one meter lead on the Yellow wire and the other on the controller where the Yellow wire came from. I believe that the ECM is switching the positive, but you might want to verify that. If it is then the Black lead to your DVM goes to the controller and the Red goes to the Yellow wire. Once the controller kicks in you may have to turn the DVMs range switch to a lower setting, but ALWAYS start with the highest setting first.
To verify if the positive is being switched - BEFORE you disconnect the Yellow wire check it to ground on a VOLTAGE scale. If it reads 0 Volts then I was wrong and the leads need to be Black to the Yellow wire and Red to the controller when checking the current. Just to make sure --- When you're checking the Voltage, if it reads 0 then move the lead from the ground to a positive battery terminal.
 
Hmmm... been putting in a little thought on this onesince the other day and I think:

- a momentary switch to the relay control might work here... but...

- without a diode in the line, you would be at risk of feeding voltage back into the PCM, especially after the PCM quit sending the signal for the initial glow cycle. If there's a way to fry something, I can find it :D

Personally, I like Chris' setup better, for that reason; it isolates the glow circuit from the PCM. It's a little more wire and expense, but I know darn well it's safe.

Just my humble opinion. Of course, I've been wrong before... or so my wife tells me :)
 
Last edited:
Great writeup, Chris. This is exactly how I was planning to do mine.

The ONLY thing I would want to do differently, which I am trying to figure out how to do, is to have a timer type switch (haven't been able to find one for 12v applications, so if anyone has any suggestions, that would be awesome) with a knob that you can set up to 25 or 30 seconds, max, then have that be the entire GP controller, rather than the PCM (once I convert to DB2, I have no need for the PCM anymore, so I would like to get rid of it.) Anyways, you could use that knob to crank up to 30 seconds on a very cold morning, plus it would automatically turn off.

I just need to find such a switch.
 
I just need to find such a switch.

It's called a push-button switch and "one-one thousand, two-one thousand, three..."

Just kidding! Have you tried a place like Mouser Electronics? They have some hard-to find things. It would be best to call them, though. Not sure of their phone number (depends on where in the world you are), but website is mouser dot com.
 
The oil pressure switch/sender has been the topic of a couple of Diesel Page articles, but instructions for changing a bad one hasn't made it into the "Page" till now. I recently discovered the lift pump wasn't being powered up in my 1994 6.5TD Chevy Blazer, and I quickly discovered the oil pressure switch as the cause. This article will show you what tools are necessary (and where I bought them), and I'll show you how I changed my switch.

I FOUND THIS QUOTE THAT A FRIEND TOLD ME ABOUT anyone have any input about it.
becasue i found a few bad grounds and that seem to fix the fuel and alt gage in the dash
but still haven't found out why my oil pressure gauge is sticky like, and the temp gauge doesn't work at all. i really like this truck its great tool.
thanks again
 
Back
Top