[kcornwell]

My A/C doesn't work until the engine has warmed up.

First thing in the AM or when the engine has cooled down, the A/C does not cool until the engine (coolant) temperature is sufficient to demand the radiator fan to run. From that point forward the A/C compressor finally engages and cools the cabin normally.

Note: This E90 has one large variable speed electric radiator fan.

Is there a relay or something? Perhaps a loose connection to check?

Thanks guys,
Kevin