This week I started having a problem with the glow plug light staying on. It would stay on 30-45 seconds before it would go out. I would drive to work with the engine light on with no problems. Get to work and plug in my Diablo predator and check for codes and it says "no codes". The glow plug light came on even in 90 degree weather this past Tuesday 20 minutes after the truck had been driven 45 miles and that just don't happen. When the temp gets above 65 you just don't see this light. Going to dealership for analysis this Friday unless someone here can give me some insight on my problem. I am leaning toward glow plug module since this all came about overnight. I had a diesel in the late 80's and the glow plugs went out very slowly over time. Is there anything else other than a module that might be wrong? I am leaving Sunday for Kentucky and gone for a week. I have two days to gets parts and fix this thing. I just don't want to pay the big bucks to my dealer when I can do it myself for the cost of parts.