I know there is a thread with a similer title but my problem is different. The wait to start light comes on and stays on, then gos off when the relays click. Its just that i dont get the voltage drop or the idle change after it starts. Would this be the relays? IAT sensor? What size socket is used to remove the IAT? Also does anybody have the part number for the relays? The guy at my dealership couldnt even find the number on his computer, then again he didnt look real bright.

 

If the wait to start lite comes on it's the IAT that senses below 66F, which it is doing. I would check for power going to the relays as there are fuseable links that could be blown. If there is power at the relays and the relays engage then either the relays are bad internally or the heater grids are fried. Someone hasn't disconnected them by chance?

 

I've seen several relays fail, usually they do it one at a time, and after about 100,000 miles. Test with a test light or an ammeter when you turn the key on, on a cold morning. Off the top of my head, the part number for the relay assembly is 56026842.