Need help locating AC switch on 72 Chevy

[smorg007]

I need help locating the A/C Compressor Switch. I was told it is behind the Glove Box mounted on the Air Box. I removed my glove box and found what appears to be a relay switch bot no a/c compressor switch. Did all 1972 chevy's with factory air use this a/c compressor switch? If so where else would it be? I'm replacing all switches and relays, hoses etc... before having the A/C looked at by A/C shop.