M1008 - Another Glow Plug problem

[glantz496]

Hello,

Ran into another interesting problem with my '85 M1008. The glow plugs turn on and warm up when I start the truck when it's cold, so I know they are working.

It seems though that they stay on continuously even after the truck has run for quite a while. I've since discovered the issue and temporarily installed a switch to shut them off to keep from burning them up. I've also checked the temp sensor and it does seem to be working as it should

Has anyone else run into this issue? Maybe poor contacts on the GP controller?

Thanks

 

[cpf240]

Has the GP relay/solenoid been replaced? If its mounting tabs are not isolated from the small terminals, it will be engaged when the key is on. Assuming the rest of the system is stock. Otherwise, the GP controller card would be my next guess.

There is a trouble shooting section of the TM that covers the GP system.

 

[timarr]

On a m1008 we have I was going through glowplugs in a short time. We changed relay and card. We watch the wait light and it would come on for second even when warm as you were driving . You would catch it out of the corner of your eye? I put in a new temp sensor and all is good!

 

[glantz496]

I'll have to check, but I'm pretty positive the temp sensor was changed once already. It looks like the GP relay was changed as well, I'll have to check the isolation on the terminals.

Thanks for the help

 

[llong66]

I had the same issue an it ended up being the controller card, pull is an check for burnt, loose components.

 

[timarr]

At 10 bucks I keep a few temp sensors around now. Its easier then ohming out to check values. part# wt300, or su109.