Experience=Mistakes Made

[Incredilion]

This morning, after doing a lot of work on my M1009, I decided to go ahread & replace the Glowplugs on my CUCV. I had bought 3 sets of ACDelco 11G (60G) Glowplugs, and since my rig was starting a little slow, I thought I'd fix that.
So, I installed them. Cut off the ends, replaced the ends with spades (I knoew I'd have to do this) and then started the truck. It started immediatley, I was a happy camper.
Got in it after cleaning up to go to town, and went to start it.
Uh oh.
No start.
After playing with this all day; my synopsis:
(A) I used 12 V plugs instead of 24V plugs.
(B) I destroyed the controller (it gives power but the ground is shot for it at the solenoid)
(C) The glow plugs are all expanded to the point of not being able to remove them. Period.

I am getting ready to roll it down the hill to the road, where a tow truck will get it in the mornnig & take it to a mechanic who will remove the heads & get the glowplugs out for me.

I don't do this kind of thing often, but when I do, I do it right.

I guess the bright side is that we're going to fix the front main seal that's leaking.
Chris

 

[dunedigger]

The plugs are 12 v anyway after ran throught the resistor block on the firewall, not 24v. I don't think you used the right plug though. You don't have to remove the head to get out a swollen plug. I have a tool I bought for aiding in removal but worse case you can usually get any broken peices out by removing the injector.

 

[doghead]

Spend a hour using the search function, or just read the CUCV forum for a couple hours. You'll find all the tricks, tools, and best parts to use.

An 11G (swell)is not the same as a 60G(rarely swell).

*CUCV's use 12v glow plugs.
*The controller card does not "give" power, it grounds the gp relay.
*there are several methods to remove swollen glow plugs, all with out removing the heads.

At anytime, if you left your key on, with the engine off and cold, you can burn out your GP's.(did you do that?)

Step By step troubleshooting procedures are in the TMs, they can be used buy an inexperienced mechanic.

 

[Incredilion]

I read a BUNCH of stuff on here after I started having issues this morning. Thanks for the tip, I've been living on this site since I got into thiese things. The suite is an awesome asset.
A couple of things-
You say the glow plugs are 12V, right? The relay that runs them has 24VDC coming to it from the firewall, on the relay side of the relay. It's controlling 24VDC, so I don't get how that gets lowered to 12VDC? I mean, the relay fires, 24VDC goes through to the other side of the realy, connecting directly to the two harnesses that feed all 8 GP's. Where does it get stepped down to 12VDC?

Doghead; help solve a mystery for me, wouldya?
On the relay, you say that it "grounds the GP relay". OK, so here's what happens:
I turn on the key, and the relay doesn't fire. I check it, and on the hot side, goes to 13VDC, on the ground side it goes to ground, but not enough ground to fire the relay. If I take a jumper onto the gound side of the relay, and then to a ground on the frame, the relay fires. Does this mean the controller is cooked?
On the Glow Plugs, and getting them out without taking off the heads, my problem is that I've backed them out all the way to the point of them just hanging there; no threads attached to break off the inside of the swell. That's the only reason I was thinking the heads have to come off, because I'm thinking that if I have to break these off in every cylinder, I'm almost bound to destroy a piston, a ring or a cylinder, somehow, right?

And now, since the glow plugs are 12VDC, I wonder what all I did today to make them swell, and not start the truck?

Thanks kindly for the advice, I appreciate it.

 

[dunedigger]

The big resistor on the firewall reduces the 24v to 12v you said you metered 13v right at the relay. Search for the glow plug removal tool, you will see how it works to remove a swollen plug. You may have had the relay stick on for whatever reason or key left on by accident? Watch this video http://www.steelsoldiers.com/cucv/61345-glow-plug-removal-tool.html if you break off the tip it will be in the prechamber

 

[Incredilion]

Dunedigger-
I metered 24VDC at the relay, (23.6VDC to be exact) on the big wire coming from the firewall. The 13VDC I got was coming in from the trigger, from the controller.
Man, I still don't GET what happened today.....
I'll order the tool & have it shipped pronto; but you don't think I should worry about pieces getting down into the engine?
I wonder if I did leave the key on, but if I did; only after it wouldn't start & I was troubleshooting. I'm not sure.

 

[doghead]

From your description, it does sound like your controller card is bad(you can manually ground the light blue wire and the GPs worked). Maybe it stayed on without you knowing it.

The 24 volt thing works like this. There is a big resistor between the battery and the glow plug relay. When there is no load(glow plugs not on) you measure 24 volts at the GP relay(there is no load/ not a complete circuit). When the GP relay is activated, the power flows though the relay down to 8 glow plugs. that completes the circuit. With a complete circuit, the Resistance of the big resistor and the 8 glow plugs, makes the voltage drop to 12 volts.

 

[Disciple]

Listen to Doghead! Just do a search on "Manual GP" or the like. You just need to throw a momentary switch between the light blue wire on the GP Controller Card and Ground. This will activate the GP Relay on the Firewall. Make sure your Relay is getting power and go from there. Again, if the GP's are swollen and stuck, first try prying them out or using the removal tool. If you can't get them out or they break off, just pull the injector right below the plug and fish the broken tip out with some stiff wire and a Needle Nose or whatever you have. This topic has been covered over and over on this site.

The toughest ones to get out are generally the rear ones because of all the obstructions, but if you stick with it, you'll get them. Oh, and don't listen to the guys who say you can just leave the broken tips in the pre-combustion chamber. Get them out. The whole project might take you half a day, but it's certainly do-able by anyone with basic tools and half a brain.

Next time get the actual ACDelco 60G's, they're "supposedly" self-limiting, so they shouldn't swell up on you.

BTW: Your next project should probably be the Doghead Starter Relay Mod if you haven't already done it.

Another thing I did was to remove the Resistor Bank on the Firewall and run 12V off the front battery straight over to the GP Relay. There are plusses and minuses to doing this, but if you don't do it and your Resistors change impedance (it's been known to happen) you will be replacing all of your GP's again. Search the topic and decide for yourself, though.

 

[mikelee]

I agree had 8 swollen ones in mine from gp controller that was bad rebuilt the card and replaced the relay (due to age) pulled the injectors to remove swollen plugs. Was not really that bad of a job. I did pull the rear battery and tray to get better access to the rear injector. total time around 2 hours. Main thing is to find as to why they failed. I know a lot of mv owners like to use manual controllers Which are fine and work well. I just prefer to have the card working and have rebuilt several with good results. I also agree using AC60G's and favor the 12 volt supply direct to solenoid eliminating resistor's. I was talking with a friend of mine considering rebuilding GP cards for SS members as long as it did not become overwhelming.

 

[Incredilion]

Doghead-
Thanks kindly for the knowledge. I never would have figured that the resistance from the glow plugs + the resistor would have dropped the voltage that much, and that's why I assumed that I did something really wrong when it stopped working. SOMETHING happened, as prior to my using new glow plugs, the truck started, just spun for too long, IMO. I think I'm going to just put a switch in & hit the button.

Disciple-
I READ all of the posts I could BEFORE I posted anything (for HOURS) hoping to NOT irritate anyone with dumb questions. Realizing it had been discussed by many before, and ALSO that there are a lot of opinions that aren't necessarily correct, I attempted to get myself straight. It worked, and thank you as well the others for the input.
On the Glow Plugs, I bought what was advertised as "AC Delco 60G/11G" plugs. My fault in that I didn't realize there was a difference between them, as the ones I bought are actually all 11G's.
The Doghead Relay was something that I did when I first got the vehicle, and I bought the second relay for my other CUCV (to be recovered in February). It will be installed prior to my bringing it home.
I ran a new cable from Battery 2 directly to the GP relay today, to INSURE I was getting 12VDC (only) before I installed the second set of new glow plugs.

Thank you all, again, for your information, I'd still sure like to know what the heck went wrong; I changed the plugs, thought I was making progress, then found out out how wrong I was. I'm thinking that what must have happened was for some reason either the relay froze up & held or the controller card messed up & held the glow plugs until they swelled. Either way, what's going to happen is that it's getting both AC60's & a momentary switch, connected directly to the relay, on both of my CUCV's.

 

[doghead]

I ran a new cable from Battery 2 directly to the GP relay today, to INSURE I was getting 12VDC

I hope you meant to say, Front battery(which is charged by Alternator 1).

 

[Incredilion]

Neg Post on Batt 2, which is where the terminal block above the GP Relay gets it's 12VDC power. It's 12VDC as it's the positive side of Bat 1/Neg of Bat 2. I got 12VDC, made sure of it by Fluke MM.
Is there a reason I should be on the positive post on Batt 1 instead of Neg on Batt 2, Doghead?

 

[mistaken1]

Neg Post on Batt 2, which is where the terminal block above the GP Relay gets it's 12VDC power. It's 12VDC as it's the positive side of Bat 1/Neg of Bat 2. I got 12VDC, made sure of it by Fluke MM.
Is there a reason I should be on the positive post on Batt 1 instead of Neg on Batt 2, Doghead?

Front battery positive and the back battery negative are the same point electrically speaking. Either one will work to provide 12V to your glow plug relay.

http://www.steelsoldiers.com/cucv/62408-story-my-cucv-12v-glow-plug-conversion.html#post739053

 

[doghead]

Either end of that "dogbone" cable is fine. In your original description, you did not mention which terminal of the rear battery you connected to for 12V+. Your good.

 

[Disciple]

You can do it by running a new cable (sounds like you already did) or you can pull the short cable that comes off the right side of the resistor bank, run that from the small distribution block on the firewall next to the GP Relay, over to the GP Relay. The benefit of doing this is that it already has a fuseable link in that wire, hopefully saving your GP Relay if something were to ever go wrong. Either way, I'd recommend putting an inline fuse in there somewhere.

 

[Barrman]

If in doubt about what is going to the glow plugs. Put a meter on the double orange wire coming off the glow plug relay. Those two orange wires turn into the 8 green wires at the plugs. Running the wire you ran, you probably for sure have 12 volts going out. Just pointing out how to make sure.