Glow System Gremlins

[Gary79F250]

Kind of a silly question, I have a 90 K3500 with a 6.2. the problem I am having is the glow system works intermitently, the glow controler and inhibit switch have ben replaced and the problem is still there. it will glow cold and hot sometime it does not glow at all TIA

 

[towcat]

Is it the solid state type and has it been relocated off the motor? I'd check your grounds and make sure the feed wires are in good shape.

 

[Gary79F250]

I done checked all the grounds, Did voltage drops on the leads, my grounds were .07V and the leads were .1V, I was more thinking a bad conection somewhere but i have not ben able to find it.

 

[Deib]

I have had that problem over and over with the solid state units. I would take it back for warranty and try another, again and again.
I think the conclusion was that there is an internal temp sensor, and that would keep them from cycling. It is not completely controlled by the external inhibit switch.

Having problems starting?

 

[Gary79F250]

Yeah, there are some problems starting, it does it's little thing intermitently, BTW, I think the pump is on its way out. Now it has a backup solenoid and push button Itsa very anice;p

 

[cgassett]

I noticed this with my 6.2 and did some research. According to Mitchel on Demand, " a normally operating system works as follows; at room temperature and with ignition on and engine off, the glow plugs come on for 4-6 seconds and the go off for about 4.5 seconds. The glow plugs then cycle on for about 1.5 seconds and off for about 4.5 seconds, for a total start sequence of about 20 seconds. If the engine is cranked during or after start sequence, the glow plugs will cycle on and off for about 25 seconds after the ignition switch is returned from the crank position, whether engine starts or not." What all that info means is that it all comes through the cold advance control and the temp sensor in the rear of the left head. I changed the sensor and start-up is fast now and the glow plug cycle is the same as it was before. I thought I'd have get some plugs and decided to try this cheap way first and it worked. Theres a complete theory and operation in the mitchel on demand that prints out nice and helps greatly. Most small auto shops have this and I'm sure they wouldn't have a problem printing it out for you in exchange for some cold lagers.