Engine/Transmission (1998.5 - 2002) Intake Air Heater?

[SWC]

I parked my truck outside the other day without plugging it in when it was -20C or around -10F. The truck would not start later when I wanted to move it. I payed more attention the second time I tried starting the motor. I noticed that the heater fan did not change speed as the wait to start light went out.

Today I checked the codes and the #1 intake heater relay has set a code but not the #2 relay. I checked the wires from the ECM to the relay and they both send a 12 volt signal to the relay so both relays are down. What has me puzzled is why after the wait to start light goes out is there an 8 volt signal to the relay? Is this enough to pull in the relay? Is this lower volt signal causing undue stress on the relay?

I will be getting new relays tomorrow.

Any thoughts on this lower volt signal from the ECM?

Thanks

Stan

 

[darkhorse]

I can see a big draw in my volt meter when the grid heaters are on. I usually turn my fan off for start so I never noticed a pitch change there. those heaters should be warming your manifold & air horn. check to see if they feel warm.