A/C Control Head problem

I replaced my A/C control head a few months back on my ’99 Silverado. I noticed that when I use the recirculator button the compressor comes on. I can also tell the air condition comes on due to the cold air blowing through the vents. On the old control head I do not remember it doing this. Any idea?

Not positive about the 99 model, but this is completely normal for my 04's. It even says in the manual that the recirculate button turns on the compressor to adjust the air humidity. The reason is that recirculating the air could cause a moisture buildup and lead to window fogging. Running the compressor dehumidifies the air so no problem. Nothing to worry about unless somebody says that this is not normal for a 99, but I'd bet it is.


I replaced my A/C control head a few months back on my ’99 Silverado. I noticed that when I use the recirculator button the compressor comes on. I can also tell the air condition comes on due to the cold air blowing through the vents. On the old control head I do not remember it doing this. Any idea?

Thanks, that is exactly what the company said from where I bought it from. The control head was redesigned in 2002. I guess you could say my truck is update to date. I just replaced the engine fan with dual electric fans. I can not believe the performance difference in power and mileage.