Glow Plug System Problems
 

I have a 1999 F-350 diesel that is having starting problems. Correct me if I'm wrong, there are two glow plug relays. If that is so, one of them is getting warm to the touch when the key is turned the other stays ice cold. I bought a new one exchanging both out, at different times, with no change. Is there maybe a fuse that might have gone bad? If so where???