Rough Idle when my fan, A/C or Heat is on...

[gnickell]

I was hopeing to get an idea of what may be going on with my truck. If I have my truck in park without the fan, A/C or heat on it idels pretty good, but if I turn on any of those it makes a click sound under the hood and idles down really low almost to stalling, it then shortly after (a few seconds) it will click again and idle back up to normal. This will happen every 10 seconds or so and does not stop whether it is cold or warmed up. It doesnt seem to happen to much when I am in drive though, stopped or moving... Any ideas? and thanks for your help.

 

[bdmaash]

there have been a few posts about seized AC compressors, and trucks not starting - may seem like a seized motor. Maybe your compressor needs attention.