AC cycling Switch

[Pauly1119]

You really should try using the OE service manual , the system operation is spelled out and easy to understand/ learn. Not to mention the wire digrams would be extremely helpful since yours is modded. Have thought about a idle kick when compressor cycles?

Idle kick? I’ve never seen that with a carburetor. I do still have the original fuse box under the hood but that’s about all that’s left but most of the fuses in it have been removed. I have a system under my dash that controls most accessories but had nothing for AC. I pulled it out tonight to look it over.

 

[Pauly1119]

I’m guessing it’s wired close to what AK49 was explaining to me, hopefully anyway. Looks like wires go from the controls to the fuse box.

 

[GoToGuy]

A solenoid on the carb' flange when AC activated, would be activated also to raise idle slightly when compressor loaded engine, preventing to low idle rpm or stalling engine.

 

[Pauly1119]

A solenoid on the carb' flange when AC activated, would be activated also to raise idle slightly when compressor loaded engine, preventing to low idle rpm or stalling engine.

How would I do that? Trinary switch? I was wondering if my fans will turn on when the compressor turns on too. I have 2 electric fans.

 

[1998_K1500_Sub]

A solenoid on the carb' flange when AC activated, would be activated also to raise idle slightly when compressor loaded engine, preventing to low idle rpm or stalling engine.

Edlebrock used to sell such a kit -- the solenoid and bracket anyway -- for their carbs. It was up to the use to decide when / how to power it.

My 1979 Camaro OE carb had one on it, as many did in the day. The solenoid didn't "cycle" with the compressor clutch, it was simply on whenever the AC was selected, so there was still some hunting of the engine RPM when the clutch cycled (e.g., at a stoplight) but it kept the engine RPM from dropping lower that it otherwise would. It could be particularly annoying with an automatic tranny at a stoplight, as when the AC clutch cycled off and the engine RPM rose it would push against the brakes.

ECM controlled engines run SO much nicer, e.g., on account of load management and other factors.

 

[1998_K1500_Sub]

How would I do that? Trinary switch? I was wondering if my fans will turn on when the compressor turns on too. I have 2 electric fans.

I would put the solenoid on the same circuit as the AC clutch, so it bumps the carb when the clutch engages.

I would power the fans through either a high-side pressure switch or a temperature controlled switch that senses the evaporator temperature. Either of those two is a good measure of whether the fans are necessary.

If you were to engage the fans at the same time as the AC clutch, the combined compressor and alternator load may be more difficult to manage / dip the engine RPM. But try it and see, if you like, that's the only way to know if it matters to you.