How do I test the Glow Plug Controller?

[The Swamphare]

Literally, there is no reason that replacing the plugs should not have resolved the problem..

 

[cucvrus]

If they are not getting power at the right time. Changing the glow plugs would have no effect. They need to be activated at the correct time for a correct start. Look and see if the voltmeter drops on start up while the wait light is on or you are activating the glow plugs. It will dip in the edge of the green slightly in the yellow on pre-glow.

 

[gottaluvit]

Yup, that voltmeter talks plain English (or whatever is your native tongue). When I first got the truck I was wondering "why a voltmeter and not a temperature gauge like so many 1 gauge vehicles have". I got that question answered when dealing with my glow plugs once cool wrather rolled around. If it don't get buried down in the yellow/orange of the gauge when you first turn the key to the "on" position, you do not have glow plugs working. It will slowly creep up to the green as the glow plugs warm up. Does your "wait" light work?

 

[Tinstar]

He's right.
Watch Voltmeter also.

I watch mine every time and is second nature.
Like watching TOT/EGT on engine startup (helo)

Totally spaced mentioning it before.

 

[Tinstar]

I was an 11B until I was an NCO. By the time I was in a unit with vehicles/motor pool, I didn't always make it to motor stables, like I should. Now I'm paying for my lack of vision...

I also was 11B at Benning.
Then Drill Instructor (E6) at Sand Hill.
Never around trucks or vehicles much at all besides POV. Rode in a bunch but that doesn't count.
After I graduated flight school, I again was not around the trucks, etc much at all.
Helos everyday yes, but only occasionally with the Military vehicles

Have worked on cars since I was 16 but the MV thing was new and a
kinda steep learning curve on the specifics of them. 5 ton especially.

This site has been, and still is, invaluable for resources and knowledge.

We are here to hopefully help.

 

[Barrman]

Somehow I missed this thread. There are several questions asked that got answered but kind of disjoined.

Driving in snow/ice conditions in 2Hi with the front hubs locked on pavement so if you get stopped all you have to do is pull the lever for 4Hi or 4LO is just fine. Yes, all the parts that are now spinning will wear faster, you might feel different vibrations and noises if any of those parts are worn or out of balance. Fuel mileage and acceleration will suffer as well. I am mentally thinking of blizzard type conditions where you have clean pavement and then a drift. Then back to pavement again. Leaving the hubs locked and just using the lever in the cab is perfect for that kind of thing.

DVOM and the TM is your friend. Follow them both as several people have already posted.

Neither of my totally stock and complete glow plug systems made any loud noises at the relay. Don't rely on noise, watch the volt meter. Don't forget there is also an afterglow cycle or two or three of the glow plugs after the engine starts. Depending on the outside temperature, it might be 30-45 seconds after engine start that the glow plugs are done taking voltage. I never hear any afterglow noises from the relays.

One stock card and one Antenna climber card. Out of the 3 glow plug systems GM used I think the military version is the best. It is the most complicated, but darn if it doesn't work right every time. I have worried in the past about the "what if" of the system going bad and needing to start the truck far from home out in the middle of nowhere in the cold. I have 60G glow plugs in all my engines and have one of those "remote start" trigger things with alligator clips on the ends most auto parts stores sell. I keep one wadded up under the fuel can holder in the back. Without messing with any wiring, I can bypass the entire glow plug system and make the plugs come on. It also lets me bypass the entire starting system and go direct to the starter if that system doesn't like me one day too.