Does the high idle control get power to it all the time when the ignition is on, or is it only energized when the ignition is turned to the start position? This is a quadrajet carb on a '81 Blazer. The engine has been changed and whoever did it didn't hook the high idle control up. If it does get power in the on position, can it be jumped to from the choke power lead or does it need its own line pulled? Sorry about these simple questions but it has been a while since I've worked on an older vehicle and the Chilton's I've ordered hasn't got here yet. TIA
============================== Some vehicles are set up for power with the key on, some with the a/c clutch and some the computer controls it. A wiring diagram is your best bet for doing it right. Either way you can run it off pretty much whatever you want. See if you can find an unused wire under the hood that was for the idle kicker. If it idles good with/without the A/C and doesnt diesel no worries.
That's the one, facing the front of the engine it is on the near right side of the carb. This Blazer had an engine swap and the air cond comp was removed. I'm trying to get the wiring diagram but haven't yet. Some of the wires were cut and I'm not certain which went to the air cond comp. Thanks.
I'm trying to get a wiring diagram, but it will be a week or so before that happens. This old Blazer doesn't have any computer controls that I am aware of. I thought it was a couple of years later that they started putting in the computers. I'll check and see if I can find an unused lead: a number of wires were cut when the engine swap took place( I'm guessing that is when they were cut). I'm not sure I understand something though. If the air cond clutch supplies the power, wouldn't that prevent the solenoid functioning when the air cond is off? Or is the power to the air cond clutch all the time the ignition is on and the clutch circuit is opened and closed on a ground leg? I just can't imagine why it would be done that way. I definitely need that wiring diagram. I've already ordered a Chilton's repair manual and am working at getting several other manuals off of ebay, a wiring diagrams manual included among those. Thanks.
There's a small box above the accelerator peddle for the electronic spark control, but it was probably disabled long ago. Look on the firewall, just behind and to the passenger side of the distributor, about even with the rotor. There is a plug in the firewall there. It had a shielded wire going through. See if anything is still hooked up to it. It went to the distributor and the knock sensor near the starter. If it's gone, that's good.
That's what it's supposed to do. The solenoid turns up the idle when the AC kicks on, keeping the engine from stalling or idling too slow.
When you turn on the ac control, it supplies power TO the clutch. The pressure switch on the side of the dryer (Light green and dark green wires going into connector) cycles it on and off with the need for pressure in the system. The idle solenoid is in parallel with the compressor. If you don't have AC, you don't need the solenoid hooked up. If you may put AC back on it, it will be tied into the same green wire that goes to the compressor. The wire is usually spliced in the harness somewhere near the carb or firewall. I really can't remember, it's been a couple of years since I yanked that harness out when I converted mine to fuel injection.
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