Ac solenoid on thermoquad
- Thread starter 71Demon
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Is it a idle solenoid hooked to the A/c clutch wiring? Kicks up the idle when the A/C is on.
I’m thinking it’s to increase idle speed when ac on
Kendog 170
Let the boy go !
I've heard of people adding them for that but not sure if factory did it. Anything in the manual ?
haven’t traced the wire but it is a blue wire so it may be from ac somewhere either control or compressor
You're thinking incorrectly. See posts #2 and #4.
So the solenoid is what sets the idle? You don’t use the idle screw on the carb?
I'll ask before looking it up, is the idle speed jacked up on a a/c car and the solenoid prevents dieseling by disengaging and causing the idle to go slower?
NOS Mopar A/C Idle Stop Solenoid 1975 Chrysler Plymouth Dodge A B Body 360 HP - Hiltop Auto Parts
Oh i see said the blind man. That’s how it works..I was thinking wrong thanks
67Dart273
Well-Known Member
To repeat, this was a "smog" device. It was to set idle speed and intended to close the carb at shutdown to try and reduce dieselling. My 70 440-6 had one, and the purpose of the large brass end where it rests on the throttle was with such engines as the 4bbl 440's which had a distributor solenoid. The throttle lever would ground the brass end, there was/ is a wire connection there, and that would activate the retard solenoid "at curb idle"
Actually you COULD repurpose this for AC. You would want to splice it into the AC clutch feed properly, upstream of the low pressure switch, which cycles the clutch off on low pressure
Frankly if you retune the engine, richen up idle, recurve the dist. and run more initial advance, etc etc, and do not have to have the car "smogged" I would simply remove the thing.
They were a PITA because most the time the solenoid did not have enough "oomph" to set the thing. You had to crack the throttle to set it. So they would almost never start and run just by turning the key
Actually you COULD repurpose this for AC. You would want to splice it into the AC clutch feed properly, upstream of the low pressure switch, which cycles the clutch off on low pressure
Frankly if you retune the engine, richen up idle, recurve the dist. and run more initial advance, etc etc, and do not have to have the car "smogged" I would simply remove the thing.
They were a PITA because most the time the solenoid did not have enough "oomph" to set the thing. You had to crack the throttle to set it. So they would almost never start and run just by turning the key
Thanks I may do that
BillGrissom
Well-Known Member
I'm with 67Dart273. I suspect the ebay seller ASSumed the solenoid was to increase idle speed when the AC compressor turns on. But, I don't recall those being used in U.S. cars until 4 cyl engines of the early 1980's when the AC turning on greatly affected idle speed. They might have transitioned them to 6 and 8 cyl engine later. Indeed, they even had to change to more efficient rotary AC compressors then too.
You can actually wire the solenoid to make it idle up for the A/C as Del mentioned, BUT, it's not strong enough to do it "all by itself". What it would do would be to engage the solenoid when you foot is ON the gas. Then it would "keep" the idle up "from there". Now......another option, and I like it and have used it a few times before is using an A/C idle up solenoid from Toyota. It's a pretty cool little deal. It's basically a solenoid hooked to a manifold vacuum source. When it sees 12V, it opens the intake manifold vacuum source to the atmosphere essentially creating a controlled vacuum leak and raising the idle speed. It has its own little filter element to filter incoming air. The addition of that small a vacuum leak has no adverse effects and does the job. Power, ground and one vacuum hose is all that's needed to connect one. Here's one.
For Toyota Vapor Canister EGR VSV Vacuum Switching Solenoid Valve 2586062010 | eBay
For Toyota Vapor Canister EGR VSV Vacuum Switching Solenoid Valve 2586062010 | eBay
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