I have fixed my AC on my 70 350 Skylark and it draws alot of horsepower at idle, so I hooked up my high speed idle solenoid to kick up the idle speed when I stop. I noticed that I have 12 volts to the switch when I turn on the key without the AC on. I thought that I should have power there only when I turn on the AC. So now this solenoid is no good to me. Is there a problem here, how can I check and fix it? Thanks Tim
Wire the solenoid in parallel with the AC compressor. Do this under the hood. When 12V is applied to the AC compressor, only when switched on, your solenoid will be energized at the same time. BTW: I thought the idle solenoids were a late'71 & '72 feature. Prior to this I thought they had dashpots only. I'm just curious here. You have modified the car?
Oops you are correct, my car is a 72........ Good idea I will rewire it, why do you suppose that it is this way now???? Thanks Tim
Emissions. Another thing it was intended was to replace the dashpot , in a way. Sounds like your solenoid may need positioning. It will slide front to back a bit once you loosen the two mounting bolts on the intake. The plunger is also adjustable by rotating it in or out. There is a lot of travel available here. Dropping from open throttle to no throttle may induce a stall condition. The solenoid would help avoid this by keeping the throttle partially open. If you left it alone, you would likely see the result you're looking for. The solenoid will only make a difference at idle. Revs above idle there is no adverse affect as the throttle is pulled away from the solenoid, by the throttle cable, connected to the gas pedal. Example: You're cruising on the highway at speed, AC on. Solenoid is energized but you don't realize because your foot is on the GO pedal.Throttle mechanism is no where near the solenoid. Your exit comes up & you get off only to find it backlogged with traffic. The engine will settle own to where you have the idle solenoid set. I have a '71 with AC. This was a transition year where the earlier cars still had the dashpot & the later were equipped with solenoid. A factory kit was available to convert it from dashpot to solenoid. This is what I've done to mine.
Steve, I understand how it works. The problem I have is that if I keep it the way it is I have no advantage of using it since the solenoid is always active I can set my idle with it but it is "on" so when I turn my AC on the engine loses too many rpm's and the solenoid is already extended so it will not raise my rpm's. If I remember correctly I used to set the idle speed with the AC on and this would make the solenoid extend and raise the idle, I would adjust the AC idle by turning the small nut on the solenoid in or out depending on the rpm's desired with the AC on. Then when I turned the AC off the solenoid would retract and the throttle linkage would fall back to the normal idle screw adjuster. My question is why or should I have 12 volts to the switch without the AC on? Tim
Not aware of the Skylark/GS cars having a direct link from the AC switch to the solenoid. I beleive the design was to have it always on to prevent the idle from dropping too low should the AC be turned on. The first idea of making the solenoid parallel with the AC compressor should work for you. BTW: Sharp car you have.
Tim, It really isn't meant for the A/C. It's an anti dieseling solenoid. There are 2 idle speeds specified. 650 in drive with the solenoid energized, and 500 in drive with it disconnected. The 71's and 72 used leaner carb metering, and higher idle speeds, which sometimes resulted in run on. When you shut the engine, the plunger retracts, closing the throttle blades, which reduces the tendency for run on. If you want to use it for the A/c, just wire it to the switched side of the A/C clutch.
