Hi, 
I'm rebuilding 3x Ambassador Gum MPU4 victim of battery leakage. 
Vinegar bath, distilled water, new outboard battery,... 
  
The machine #2 itself is good and tested with a working mpu4. 
  
I'm working on MPU4 mod4 #1A : 
On start-up I have "AG3 0.2", the 4 wheels initialise but wheel C seems blocked, lights turn on and then "AL3" message is displayed and everything is blocked. 
  
The message error isn't in the error list, any idea ? 
Thanks 
Arno