I have a 2005 Inspire with Cat C9 engine. I'm troubleshooting Inlet Air Heater, also called grid heater.
The issue is relay power. According to Cat the vehicle manufacturer provides 12 VDC ignition power to positive control terminal. The CAT ECM provides ground when temperature dictates.
I have power to the high amp connection, but no power to control terminal with ignition on.
Anyone know from where the control terminal is powered? I find no fuse with a similar name. Is it possibly powered from the Air Dryer circuit?