White smoke on startup.where is controller?

[tbyrd 63]

I have a 1993 6.5TD motorhome that has white smoke on start up. It dissapates and runs great after a minute or so of driving. Just started before the colder temps. I have 6 month old Bosch glow plugs. I belive my fuel is fesh/good. I was told it may be the controller. What does it look like? Where is it? My glow light cycles and seems to do so longer at cold temps and less so at warm.
Thanks.....I am selling this vehicle and most people do not want a MH with a GM diesel in it. All I hear is, "Oh, I am looking for a CAT" or Cummins. BLAH BLAH BLAH.. It is hard to convince them that this motor does push this rig without a problem. Expecially when it smokes on startup...

[charliepeterson]

If you pull the "dog house" off from the inside the glow plug controller should be right in front of you. It kind of looks like a distributer cap with the wires on the outside.

From what you describe about the GP light comming on and off everything should be ok. The circut going to the GP's has fuseable links controlling each side. You may have lost one side?

With a 12volt test light you can troubleshoot going to the GP's.

[tbyrd 63]

While testing for power at the plugs, how can I keep the controller from cycling off?...Thanks

[charliepeterson]

Up near the thermostat in the same pipe/crossover tube you will find a sensor sticking straight up. If you unplug this sensor the GP's will stay on much longer because the computer thinks the water temps. are really cold.

Also while the GP controller cycles off you might hear an audible click. This is the solenoid inside switching off. I'm not sure of the current passing through this to the GP's but it's up there.

It's also possible that the coolant temperature sensor might not be reading correctly shutting off the GP's too soon being Ten years old? The GP controller might not be up to the task either? With new GP's the truck should light off easy. That's assuming the mileage is low being a motorhome and not a daily driver.

The fuseable links are in the circut but rarely give any trouble. Make sure none of the fuses in the circut are bad.