glow plug blowout

[TedO]

Hello, I just found my M1008 doesnt start and I feel that the problem is the glow plugs arent working. The light still works, but it stays on for much longer than it usually does.

I checked the voltage to the relay and I read 24 volts (although I didnt disconnect all the glow plug leads.) Looking closer at the relay, it looks like it is a 24 volt relay(???). Never noticed that before. I am just getting into this.

I am going to check the resistance on the resistors. If the resistors burned up, what am I looking at? Are all the glow plugs fried? How could this have been working for 2 years with a 24 volt glow plug relay?? I assume I am looking at replacing the resistors, replacing the relay, and new glow plugs. I am updating the controller card too. Anything else I should do? Is this just the tip of the iceberg??

 

[firefox]

Wow. The relay is supposed to be 24v with a 12 volt coil which is controlled by
the control card, I would suggest you read up on this. There is a lot of
info in the stickies. other folks will chime in, be patient.

 

[TedO]

If the relay is supposed to be 12v, then I guess it is OK. I thought the 24 volt was supposed to be stepped down to 12 by the resistor. Maybe this is simpler than I thought.

 

[firefox]

Yes, it is pretty simple. The reason for it is so that
you can get jumped from a 24 volt truck thru the
NATO cable. I suggest checking the glow plugs.

 

[cpf240]

If the relay is supposed to be 12v, then I guess it is OK. I thought the 24 volt was supposed to be stepped down to 12 by the resistor. Maybe this is simpler than I thought.

Yes, the glow plugs are supposed to see 12v, not 24v. However, without a load on it, ie the glow plug relay engaged and all the glow plugs working, you won't see 12v at the input side of the relay. If the glow plugs are supposed to be on when you are making that measurement, and you are seeing 24v, then all the glow plugs are probably dead.

 

[MarcusOReallyus]

Let me try to make it simple:

The GP resistor steps down the voltage only when current is flowing, in other words, when the GPs are working. That means the controller card has engaged the GP relay to allow current to flow to the GPs.

When everything is right:

1. If the GP relay is energized, then current is flowing, and you should see 12v at the input of the GP resistor, and 12v at the output.
2. If the GP relay is not energized, then no current is flowing, and you should see 24v at the input of the GP resistor, and 0v at the output.

When all of your GPs are completely fried (open):

1. If the GP relay is energized, no current is flowing, and you should see 24v at the input of the GP resistor, and 0v at the output.
2. If the GP relay is not energized, no current is flowing, and you should see 24v at the input of the GP resistor, and 0v at the output.

When some of your GPs are completely fried (open) and some are good:

1. If the GP relay is energized, some current is flowing, and you should see somewhere between 12 and 24v at the input of the GP resistor, and the same at the output.
2. If the GP relay is not energized, no current is flowing, and you should see 24v at the input of the GP resistor, and 0v at the output.

But check that relay to make sure it's working. Sometimes the contacts can get carboned up and won't pass enough current to light the GPs.

 

[TedO]

Thanks. That is a good explanation.


I found this flow chart that I found to be very useful to track down problems. It has all the voltages listed. It is here:

http://radionerds.com/images/c/ca/CUCV_Glow_Plug_System_Diagnosis_and_Troubleshooting.pdf

After going through this flow chart, it looked like the problem could be just the relay. There was no voltage coming out of the relay to the glow plugs, and the full 24 v was at the red wire going in to the relay, and there was voltage on the blue ground wire. I switched out the relay in 10 minutes, and the truck runs fine now. I am going to switch out the glow plugs with the Bosch duraterms because my plugs have been running for 3 years. I have the 60G's on there, with the blade connectors swapped out for the 1/4" connectors.

I was out on the street working on the truck last night right when Trumps election fortunes started changing. My neighbors were not very happy about it. They were walking around in a state of shock, but then they are abhored by the fact I have a CUCV parked out there and not a BMW or Lexus. They are always trying to hassle me about it. Every time a drop of oil comes off of it, they are out there with cameras.

 

[PETE BALLARD]

TedO, sorry to hear about your neighbor problems- you are not alone!
back to your problem- you need to confirm your glow plugs are powered by 24 volts. If so, you need to understand the design is to get 110 % performance out of them- the system is designed to use 12 glow plugs and to run all 8 of them on 24 volts which when they are all operational is fine- however when they start to fail every time one drops out of the circuit the voltage increases for the remaining operational glow plugs which set you up for what they call a "cascading unit failure". Periodically you need to confirm they are all operational which will prevent your present situation. It looks as though you have repaired your problem and is good you understand the how and why of how your glow plugs work if they are still configured as the vehicle was new.

 

[rustystud]

.

I was out on the street working on the truck last night right when Trumps election fortunes started changing. My neighbors were not very happy about it. They were walking around in a state of shock, but then they are abhored by the fact I have a CUCV parked out there and not a BMW or Lexus. They are always trying to hassle me about it. Every time a drop of oil comes off of it, they are out there with cameras.[/QUOTE]

Tell them the next time you see them taking pictures and giving you crap that since you don't feel the "love" you plan on getting a 5 ton truck to help with your depression !

 

[Tinstar]

.

I was out on the street working on the truck last night right when Trumps election fortunes started changing. My neighbors were not very happy about it. They were walking around in a state of shock, but then they are abhored by the fact I have a CUCV parked out there and not a BMW or Lexus. They are always trying to hassle me about it. Every time a drop of oil comes off of it, they are out there with cameras.

Tell them the next time you see them taking pictures and giving you crap that since you don't feel the "love" you plan on getting a 5 ton truck to help with your depression ![/QUOTE]

That made me laugh out loud.!!

 

[the skull]

.
Tell them the next time you see them taking pictures and giving you crap that since you don't feel the "love" you plan on getting a 5 ton truck to help with your depression !

Oh I am feeling so depressed these days, I'm going to wake up my wife and tell her there's a 5 ton missing from my life right now!

 

[Ando427]

TedO, did you figure out your starting problem? I'm in San Diego as well and just recently picked up my 1009. It's been having starting issues as well that I'm trying to track down. Where did you go for a new glow plug card?

I too had a run in with my BMW driving neighbor. He got quite angry that I parked in front of his house (parking in front of my house was full), and he ordered me to move my truck. I told him I'd get around to it when it was convenient for me and that in the future if he wants a favor from someone he should ask instead of making demands. He later came over and apologized for his rudeness and gave me a bottle of wine (no ill effects yet from drinking the bottle).

 

[german m1008]

New glowplug controller cards......
http://www.glowplugcards.com/