Hi idle stuck on, why?
- Thread starter Greg5OH
- Start date
bbjordan
Snow Monkey
If you unplugged it and the idle dropped, either the engine was not up to temp, or the temp switch is stuck on. When the engine is cold this switch is normally closed (current goes thru it), but when the engine is warm enough, the switch opens and the high idle solenoid is de-energized. Same with the cold advance solenoid. They both get energized thru the same switch. This switch has two spade connectors and hides behind the thermostat housing.
Was your engine rattling a bit more when it was warm? Or did it run better? If it ran better, your timing might be too retarded.
Was your engine rattling a bit more when it was warm? Or did it run better? If it ran better, your timing might be too retarded.
icanfixall
Official GMM hand model
The above posting describe really well whats going on. That sender behind the thermostat housing is really tuff to get to. When it sees coolant temps of 120 degrees it opens and shuts down the advance and fast idle all at the same time. You probably will have to remove the thermostat housing to get that sender out of there. Kind of a big job too. If your V belt dirve then the alternater needs to be removed to get at the stat housing bolts. Coolant needs to be drained down some too but cane be reused..
It is hard to see, but I have a v-belt truck and I didn't have to take anything apart to get to it. I just had to get a piece of plywood and set it on the pass side battery and radiator support, and then climb up on the front bumper and use the plywood to help support me as I leaned over behind the alternator to unplug the sensor/switch. I did this several times, as I found out my switch went bad, and I experimented with a manual switch hooked into the factory plug and run into the cab. That's when I found out the whole setup is not really needed for the truck to run properly, and I did not need to spend $50 for a new temp switch. Mine doesn't work and it seems to run fine.
