6.2 diesel Fast idle/timing advance control circut question

[excessiveego]

When I got my blazer the fast idle, timing advance, and glow plugs were all unhooked. I got the glow plug problem squared away but to get it to start, even when the air temp is 70* I need to cycle the glow plugs twice and hold the pedal to the floor.

It cranks for about 5-10 seconds then starts right up, but I need to hold on the pedal for a few seconds until the idle smooths out or it will stall. Once it starts it will blow white smoke for 15-30 seconds, I originally assumed this was due to the longer cranking time and extra fuel being dumped into the cylinders. When the engine is at operating temp it starts instantly with no smoke.

I figure the next logical step would be to hook up the fast idle and timing advance and see if that makes a difference. I'm not sure if it will, but my diesel experience before this is strictly with tractors which only need timing advance when starting below freezing.

Now to my real question. Does someone have the wiring diagram for the fast idle and timing advance circuit? I have the haynes manual that doesnt even cover diesels and the chilton manual which covers diesels but only has one paragraph on the timing advance and no wiring diagrams on it.

 

[tRustyK5]

Cold advance is pretty simple. There is a temp sender at the rear cylinder head, should be passenger side. When below a certain temp it allows 12 volt to the cold advance terminal on the IP. My 6.2 is missing the sender, I think it went missing when I did head gaskets. I set up a switch in the cab to manually do the cold advance...works just fine and makes a world of difference starting it.

Should be a dark green wire that goes to the cold advance solenoid.

 

[excessiveego]

so does the sender switch power or ground? Usually they switch ground.

 

[tRustyK5]

Pretty sure it's ground interrupt...