When I use the remote start on my 08 burban on warmer days, the vehicle starts. So far so good. Sometimes on warmer days(not all) when the A/C goes to automaticly kick in there is this loud rapid clicking that sounds like the A/C clutch engaging and disengaging very fast. It does it for maybe 5sec and then is fine. Both the front and rear A/C are working well. I thought it might be a little low on coolant, or the high pressure switch? Has anyone else had this issue?

 

I assume you meant "low on refrigerant", not coolant. Have you tried having someone start it while you watch the compressor clutch? When it does this, have you tried shutting it down for a short while and restarting to see if it repeats?