Looks like the output from the computer that fires the starter relay.Over the last couple of years my a/c has been not fully putting out the way it should. After cleaning cab filter and blowing out dust in evaporator also found heater selector was allowing some flow that didn't help. I finally found the problem. I removed the intercooler and found the center of the condenser plugged. I blow the radiator and oil cooler often but wasn't getting the pressure to the a/c condenser . Once it was cleaned the a/c was back to normal. Tip I made a nozzle from a 1/8 stainless steel air nozzle flattened with a hammer drilled 2 3/32 holes in it now I can slide in to blow out condenser.
Another problem I have is code 73. Does anyone know what causes that code?
Maybe a bad relay, or a loose connection.