Relay chatter under the dash

[snock]

First off, my M1009 starts and runs fine but every time the glow plugs cycle there's a relay under the dash that does a fast on-off chatter for a split second. When I go to start it I get the usual "wait" light which then goes out and I start it. Then it runs for a bit and the relay then does the chattering. I notice that the glow plugs must still be on after the wait lamp goes out because my volt meter is low. After the relay does it's chattering it goes up into the green.

Anyone ever have this issue before? I figure if anything it's the glow controller but I thought I'd ask here first.

 

[Boner]

mine does the same thing but my battery gauge doesn't work. did you figure it out yet? mine does it when I turn the key in the on position without even starting the engine too.

 

[Wolf.Dose]

What is the mileage of your truck? Arround 120,000 miles the glow module starts to fail. The other two relais under the dash are simple Bosch relais, available allmost everywhere (at least in Germany), so simply change then as required to new ones.
If your glow plug module refuses to do its job propperly, you easily can blow your glow plugs for the have no thermal regulator incorporated in the plugs. This regulation is planned to be handled by the glow module.
Glowing time at the max of the original glow plugs is 7 seconds, which is almost the timing of the seat belt busser. If you glow longer at full current, you will hear a slide cracing noise, which means, your glow plugs just said good by.

Alternatively you can use the HUMMER plugs, which are 24 volts with regulator core. You have to modify the harness, the connectors do not fit. Then glowing time is not limited any more.
Wolf from Germany

 

[Boner]

I don't think that's it. My truck still runs after this happens so, if the glowplugs said good-by, why does it still run? Maybe it's the seatbelt buzzer trying to work, I have not heard a seatbelt buzzer one time from this vehicle.

Parking brake light and seatbelt light won't go off though...maybe brakelight-switch is off mounted.

 

[linx310]

Mine has started doing this also. It could be because of the really cold weather we are having here.

 

[Milbikes]

When cold, after the truck starts and the wait to start light goes out, the controller still supplies voltage (Through the relay) to the glow plugs. After a short while, the relay "Chatters" as it turns off. Mine has done this since I got it, and no problems so far.

My 6.5 civilian Chevy also keeps power to the glow plugs after it starts, but does it in a series of on-off bursts.

 

[ralbelt]

No chattering. Temps as low as zero in the last few weeks.

 

[1stSarge]

Low battery voltage.
Loose/dirty/corroded connections.
And another, I touched on in this thread:

http://www.steelsoldiers.com/cucv/62606-86-6-2-glow-plug-module-repair-3.html

Look at post #26

 

[mistaken1]

Relays are not supposed to chatter.