Please forgive me If I put the questions the wrong way (I'm a female with little knowledge)
1. AC blows warms air. starts off cool then goes warm in a little while. I believe AC relay changed but power or connections not right at the "ground".

2. Engine just cuts off at red lights or idling in a line of some kind. Starts right back up. Doesn't do it every single time but a lot. Engine sounds like a couple of coughs before going dead then will restart right away.

Any help out there is much appreciated.
Thanks, Bamapam1

 

I will answer in order.
1. Make sure the a/c compressor is rotating when the conditioned air goes warm.

2. Verify that the fuel pressure is at specs. Sounds like either low or no pressure when the engine sputters before stalling.

I would run a code scan to see if any stored codes are present and could provide some insight and direction to the stalling issue.
I suggest having a technician check your G.M. for you.