Try these two things:
1. Look under each roof unit (from inside) for the telephone plug connector boxes and clean the contacts. I had to replace my boxes because some condensation water had corroded the contacts. The control will not light up or work if these ceiling contacts are bad.
2. SYSTEM RESET
a. Turn the ON/OFF switch to “OFF” position.
b. Simultaneously depress and hold the MODE and ZONE
push-buttons while turning the ON/OFF switch to “ON”.
FF should appear in the LCD display until the MODE
and ZONE push-buttons are released.
#1 fixed mine then I did # 2 but you can try them in any order.
Ron & Peggy Carter
2004 M380 BB Wanderlodge; 2010 Enclave/M&G Brake
Punta Gorda, FL