Help: A/C Idle Solenoid Problem - The 1947 - Present Chevrolet & GMC Truck Message Board Network

BigDave · 07-21-2003, 11:20 AM

I'll keep this short. I installed twin 12" fans on my Cheyenne with the 402. While it was parked and I was testing the system I noticed the A/C solenoid wasn't working.

I purchased a new one Saturday and installed it yesterday. Everything seemed to be okay after the install and it idled fine. When I drove the thing to work this morning it was racing like crazy when I got it into park.

I turned the A/C on and I didn't notice a change in the idle. When I turned it off I didn't notice a change either. When you start it, if you don't touch the accelerator it will idle fine. As soon as you depress the pedal, it will kick it the idle up too high.

Isn't this device supposed to increase the idle when the A/C is activted and return it to normal when the A/C is off? Why would it be causing the engine to race. I just assumed you unscrewed the old and screwed in the new. I've replaced these before and have never had this problem.

BigDave · 07-21-2003, 09:22 PM

C'mon guys 26 views and no one can help me out.

If you're facing the carb from the front the A/C idle solenoid is the cylindrical tube attached to the right side of the carb with a "foot" that kicks the idle arm on the carb.

Mine does not appear to be kicking when the A/C is activated. It appears to be activated as soon as the key is turned.

tom hand · 07-21-2003, 10:00 PM

That is an anti-deseling solenoid. It is supposed to come on any time the key is on. You set the idle with it with the key on by turning the hex end "foot". When you turn the key off it completely shuts the trottle so there is no run-on. It even came on modles that did not have A/C

jimfulco · 07-22-2003, 02:40 AM

I modified it for an A/C throttle kicker (rewired to A/C clutch) on my 72 Nova.

BigDave · 07-22-2003, 10:18 AM

Quote:

Originally posted by tom hand
That is an anti-deseling solenoid. It is supposed to come on any time the key is on. You set the idle with it with the key on by turning the hex end "foot". When you turn the key off it completely shuts the trottle so there is no run-on. It even came on modles that did not have A/C

WOW!

Learn something new everyday. That's really strange because now that you have described it that is exactly how it is working. However, the part is described in all the parts books I have seen as an A/C Idle Solenoid.

This then brings a question. Why then have vehicles I have owned in the past had this solenoid working in conjunction with the A/C? Weird.

BigDave · 07-22-2003, 10:20 AM

Quote:

Originally posted by jimfulco
I modified it for an A/C throttle kicker (rewired to A/C clutch) on my 72 Nova.

I'm gonna do that. When sitting are red lights the A/C and the electric fans draw down the amps. A few hundred RPMs would help that a lot.

Bilgewiper · 07-22-2003, 03:46 PM

On a 74' I used to have I wired it to a switch on the dash and used it to help bump idle during the winter and for upping idle with A/C on in summer.

07-21-2003, 11:20 AM	#1
BigDave I poop on Ford! Join Date: Apr 2002 Location: Houston Area Posts: 295	Help: A/C Idle Solenoid Problem I'll keep this short. I installed twin 12" fans on my Cheyenne with the 402. While it was parked and I was testing the system I noticed the A/C solenoid wasn't working. I purchased a new one Saturday and installed it yesterday. Everything seemed to be okay after the install and it idled fine. When I drove the thing to work this morning it was racing like crazy when I got it into park. I turned the A/C on and I didn't notice a change in the idle. When I turned it off I didn't notice a change either. When you start it, if you don't touch the accelerator it will idle fine. As soon as you depress the pedal, it will kick it the idle up too high. Isn't this device supposed to increase the idle when the A/C is activted and return it to normal when the A/C is off? Why would it be causing the engine to race. I just assumed you unscrewed the old and screwed in the new. I've replaced these before and have never had this problem.

07-21-2003, 10:00 PM	#3
tom hand CCRider Join Date: Feb 2000 Location: Olive Branch,MS,USA Posts: 2,232	That is an anti-deseling solenoid. It is supposed to come on any time the key is on. You set the idle with it with the key on by turning the hex end "foot". When you turn the key off it completely shuts the trottle so there is no run-on. It even came on modles that did not have A/C __________________ 72 GMC Sierra SWB almost finished---- 84 Softail Olive Branch MS

07-22-2003, 03:46 PM	#7
Bilgewiper Registered User Join Date: Dec 2002 Location: Citrus Heights Ca. Posts: 186	On a 74' I used to have I wired it to a switch on the dash and used it to help bump idle during the winter and for upping idle with A/C on in summer. __________________ Ethan '71 C-10 LWB Cheyenne 85K miles. "Time spent Boating is NOT deducted from ones lifespan".

07-21-2003, 09:22 PM	#2
BigDave I poop on Ford! Join Date: Apr 2002 Location: Houston Area Posts: 295	C'mon guys 26 views and no one can help me out. If you're facing the carb from the front the A/C idle solenoid is the cylindrical tube attached to the right side of the carb with a "foot" that kicks the idle arm on the carb. Mine does not appear to be kicking when the A/C is activated. It appears to be activated as soon as the key is turned.

07-22-2003, 02:40 AM	#4
jimfulco Registered User Join Date: May 2003 Location: Shreveport LA Posts: 3,170	I modified it for an A/C throttle kicker (rewired to A/C clutch) on my 72 Nova.



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