2002 Buick Regal electric glitch

Once in a while when I start the engine, the heater fan, rear window defroster, air conditioner, and cruise control, won't work.

All other elec equipment works fine. Then after a few minutes, it all come back on and works normal.

I suspect a relay but, haven't been able to associate all the problem electrical devices to one relay.

I have had some luck, restarting the car a few times, and this sometimes brings back the non working items.

what do you think is wrong?