A/C solenoid

[Ricks72Chlgr440]

Those of you who installed an aftermarket A/C solenoid onto your carb; where did you get the power from? Did you splice into the compressor hot wire with a tap, or did you solder a wire into the comp hot wire? Wondering the best way to do this.

 

[mopar jack]

If your car came with an anti run on/diesel solenoid I would tap into that source. I recently installed a Vintage air system and with a 440 set to idle at 900 rpm haven't needed a solenoid.

 

[Ricks72Chlgr440]

If your car came with an anti run on/diesel solenoid I would tap into that source. I recently installed a Vintage air system and with a 440 set to idle at 900 rpm haven't needed a solenoid.

The car did not come with that so looking for what others have done to get power. Also, I have the VA A/C setup too. The car came with dual electric fans and the VA setup. When the fans come on, the engine RPM's drop a little. When that happens and then the A/C comes on the engine struggles, especially when the auto trans is in gear. Up to now I have had the idle set higher to compensate some for that but don't think that is the solution. Hoping the solenoid can mitigate some of this.

 

[Litchkar]

I did this on my 371 Stroker with a Vintage air system. I tapped off the compressor power lead. Works great, but sometimes I have to bump the throttle to get it to engage. The solenoids are not strong enough to push the linkage to raise the rpm’s, they extend and lock open to prevent the linkage from fully closing when engine is above idle.

 

[cuda joe]

i taped into the ac compresser power wire the only problem i have with that is when the ac cycles off at idle then kicks back on at idle the solenoid does not have the power to up the idle i have to tap the gas

 

[Ricks72Chlgr440]

i taped into the ac compresser power wire the only problem i have with that is when the ac cycles off at idle then kicks back on at idle the solenoid does not have the power to up the idle i have to tap the gas

Yeah, I think these are pretty useless. Since the solenoid does not increase the idle speed by itself, I wish I would not have purchased it. What I *might* do is use it as an anti-dieseling solenoid instead. Need to increase the idle a lot to handle both the compressor load and the alternator (especially when the fans come on). Hmmm... something to think about!!!

 

[Xcudame]

Factory AC equiped cars did have a higher idle setting. Like an additional 100 rpm or so. Ricks72Chlgr440, what is your current rpm in Park at idle? 950rpm or less I would think is definitely acceptable.

 

[Ricks72Chlgr440]

Factory AC equiped cars did have a higher idle setting. Like an additional 100 rpm or so. Ricks72Chlgr440, what is your current rpm in Park at idle? 950rpm or less I would think is definitely acceptable.

Unfortunately, not much of my setup is factory! To keep the engine happy, I have to set the idle at about 1100. In gear, with A/C & cooling fans running the engine is at about 750 and not particularly happy. Timing is optimized so that eliminates the issue being lack of timing. I often need to shut the car off in gear to prevent dieseling.

 

[Xcudame]

You've discovered why they installed the idle solenoid on carburetors!

 

[cuda joe]

i would wire the solenoid to stay on whenever the ac is on if you put a thermal switch to cycle the compresser on and off the compresser wire isn;t the best choice but will work you will have the problems i stated above

 

[Ricks72Chlgr440]

i would wire the solenoid to stay on whenever the ac is on if you put a thermal switch to cycle the compresser on and off the compresser wire isn;t the best choice but will work you will have the problems i stated above

I contacted Vintage Air about this. Their system does not have a way to grab 12v when the system is on. The only 12V cycles through the system when the compressor comes on. The fan speed and temp control use a zero to five volt scale. In light of this, I wired my solenoid up to come on when the ignition is on and shuts the carb blades when off. Basically now an anti-diesel setup. Not what I really wanted, but will do.