CE comes on when you run the A/C?

[bwheitman]

This is a strange one! if I run my A/C my engine light comes on. I dsiconnect the battery and then reconnect to reset the light, but if I turn on my AC in the morning while the engine is cold the darn "check engine" light comes on. Any ideas? Thanks,
Brian
1996 SL320, 108k, maintenance all up to date.