Hello everyone! Ok, first off I did search and read about 200 threads for grid heaters and wait to starts and didnt find any real matches to this problem. Heres the problem, sometimes the wait to start light comes on and sometimes it doesn't. The truck can set outside on a 10* night and turn the key and no light! Cycle the key a few times and it might finally come on, then the truck starts fine. Sometimes when it comes on it goes out after 2 or 3 seconds, not long enough to do anything!!! It acts up reguardless of how cold it is. Last saturday it was around 50*, truck was warmed up from driving, stoped at a greenhouse for a few minutes, came back out and no light and cranked but didnt start! Tried the key a few times and finally got a wait to start light then it fired up just fine. Im assuming there is a sensor that is going bad and not calling for the wait to start/ grid heaters but maybe its somthing else? Just dont want to get stranded somewhere if it completely craps out on me! Thanks for any input.

 

I bet its your temp sensor on the front of the truck, or your IAT is dirty.

 

Is there any way to check either of the sensors to see if they are bad or narrow it down to one of the two? What would be a good way to pull and clean this "IAT" sensor? The truck has never had the check engine light come on so I assume the computer hasnt realized anything is wrong yet. Thanks for the info!

 

I'm not huge on the 24v engines, so I'd do a search here and see what comes up.

On my 12v the IAT is towards the back of the motor on the drivers side of the head on top.

And the temp sensor is located right under your hood, on the front of the truck by the drivers headlight. (I think - cause thats where it is on mine)

 

Thanks again Digital Bullet!

 

Here is a link to the IAT information.

http://dodgeram.org/tech/dsl/sensors/IAT/clean.htm

 

I have a buddy who needed this at the top; curious about your outcome and if this was your problem. thanks, bruce

 

it should still start pretty easilly in 50* with no grid heater though...no?

 

I have the same problem. Bob Wagner says it is the ECM. I have not replaced that but I will probably have to one of these days.