glow plugs suck

[Wartburg]

I have a M1008 that I picked up from the city garage two years ago. It has had some major tinkering on the wiring before I got the truck (It is still a 24volt starter). When I got the truck I could hear the glow plugs cycle (click on and off) and the tuck would crank. It has stopped cycling and I changed the glow plugs (the ones I took out are not 070 that I understood to be the correct ones), and changed the glow plug connectors. I started to change the glow plug solenoid on the fire wall but noticed it looks different than any others that I have seen pictured on here. I am not certain but they might have change it out to the 12 volt glow plugs and solenoid?? I can see the starter relays is still stock. I have been looking at some of dogheads post and other guys glow plug post. from what I have read this is a common problem with this truck I picked up a 24 volt solenoid from napa (N1343) so that I could bypass the starter relay but have not put it on yet the starter has never hung. I pick up some 070 glow plugs and put them in but have changed them back out to the 12 volt glow plugs.. I am lost and just change parts here. I have a volt meter but suck on electics. plus spelling. sorry to bother you with a common problem and thanks for your time. should I just buy stock in starter fluid?? One other thing that I am certain is because of the glow plugs but when I start the truck and it runs threw the hi speed ideal it will sometimes die and is very hard to start. It is like a gas engine flooding??

 

[l1a1man]

Yeah, I have been wishing spark plugs would work instead about right now too.

 

[Scarecrow1]

This is a common problem meaning the wiring . Almost everyone having problems start out by saying some one tryed to convert the truck to a 12 volt system. I dont have one of them thank goodness , but if I were you I would invest in taking it to a good electrical shop and have them put it back to the stock wiring . Or at least get a diagram and trouble shoot it until you find out where they started to rewire it and then reverse it . I think the starter is 24 volts anyway so it hasn't been altered yet. I'm sure someone has had the same thing so don't give up hope

 

[ida34]

The 070 plugs are 12 volt glow plugs also. The AC Delco original number is 13G while a lot of people put in 60G AC plugs when they upgrade. The terminals a different so you have to change them for the 60G plugs. The military went to the Wellman 070 plugs later. Two of my cucvs had 13Gs while one had 070 Wellmans. Before you keep changing stuff get out a multimeter and the -20 manual. I will post a link. All the manuals are listed under the resources tab. They all have the same starting numbers for the same series of equipment. The cucv manuals start with TM 9-2320-289-xx. The xx is replaced with -10 for operator's manual, -20 for the unit level maint manual, and -34 for the direct support manual. If there is a P after the -20 or -34 then it is a parts manual only. I will post a link to the manuals in a minute. Under the electrical troubleshooting part of section 2 there is a step by step chart for troubleshooting. Most things can be checked by pulling the glow plug module and probing the connections at the plug case to check against listed result in the manual. There should be a large resister on the firewall in the center with a metal cover. This should be where the glow plug relay gets its power. When under load it drops the voltage down to around 12 volts from 24 volts. Check for voltage coming out of the relay when the glow plug light is on. If it is giving out voltage when activated then it is working. Then inside and check by the -20 list at the glow plug module connector. You can not go wrong by going by the manual. The only question is if the removed the resistor from the system when they hacked it up.

 

[ida34]

Go to page 2-62 of this manual.

TM 9-2320-262-20

Here are links to a page with the other manuals for download.

Page with manuals.

 

[ida34]

BTW the manuals have a figure section in the back with has wiring diagrams. The glow plug troubleshooting part of the manual above has a glow plug system wiring diagram.

 

[Wartburg]

Guys, thank you for your time. I always get a ton of great info on here from you guys. Have a great christmas.

 

[Wolf.Dose]

Beside the system works well as long as new, the system has a age problem. Over 120000 miles and a age of 20 years the glow plug controller starts to fail. Some of the electrolytic capacitors refuse to do their job for they are dried out. So the controller fails. If you exceede the glowing time without a propper controller, the 13G glow plugs will burst after a maximum of 6 seconds, for they are quick glow plugs without regularor.
There are some possibilities: One is to change to 24V Hummer plugs without pre registor and make the preglow manually. The 24 Volt plugs incorporate a regulator, so they can not blow up under normal circumstances. The registor on the fire wall is aboslute.
Other possibility is to install a timer where you have to be aware not to exdeed the 6 seconds of pre glow time manually before starting (contol light required).
Or you find a controller / computer / radio / TV repair shop which is qualified (and willing to do this kind of repair) to change the electrolytic capacitores to an acceptable price.
Wolf

 

[ida34]

I would watch manual operation of any glow plug system. Any glow plugs will swell if abused enough.

 

[Wolf.Dose]

The glowing harness page says nothing about the interior derign of the controler (I own the related manual). You need the diagnostic system to find out whether the controler is ok. But who owns a military diagnostic system!
Electrolytic capacitors have a live time of about 15 to 18 years, than tey dry out. For the propper function of the controler they need to be replaced.
Wolf
autombile engineer