01 Impala A C Intermitant

Sometimes it wont come on, but then again, when I drive over a expansion joint on a bridge span, it’l come on and work for two or three days. I suspected a relay, but it happens only when the dash temperature gauge is also not registering. Coolant temperature sending unit bad ??? Computer not recognizing engine temp??? What gives??

Managed to survive all last winter …but, it’s JUNE

Sounds like a bad ground or loose connection somewhere.
Do not use the A/C until it’s fixed as a loose connection is a fire hazard and can also cause compressor damage from undervoltage operation.