the light for "wait to start" comes on when i start the truck and never goes out

 

My cousins truck did that and he started the truck and drove it anyway only to have a fire under the hood. His heater solenoid stuck and it caught the heater circuit on fire. Not saying this is definitely it but just in case.....

 

I believe that the grid heater has the only "important" input to the WTS light, you should check the electrical path on it.... the above post should give you PLENTY of motivation to do so!

 

Looks to me that the ECM controls Grid Heaters and the ECM turns on the WRS light. I would check to see if they are actually coming on. I would not drive with them on continuously. If you have to pull the relays.

 

ditto on that one.

 

I had this happen to me as well. Short term you can replace the computer control on the ground end of the heaters with a toggle switch in the cab. At least that way you can run them before you start it and then turn them off till you can change out the ecu. I ran like that for most of a winter. The ecu is $$$ :-(.

I am sorry, i dont know which wire it is in the harness but I am sure someone here has a manual handy.

-Matt