I have an issue that I'm trying to get dialed in. I recently had some work done to my 2005 6.0, I upgraded my turbo and had an egr delete done on it. This was done in the summer so the issue I have hasn't come up until now. I drove my truck the other day when it was close to zero outside and I had no heat, I drove about 15 miles and stopped at a store after the initial trip I went a few more miles down the road and the heat was working. Then after driving again I had no heat. For some reason the heat seems to come and go whenever I cycle the ignition, I know all about the light switch problem on the climate control panel, it's happened to me several times during my ownership, this heat thing is new to me and I haven't seen anyone else post about it....help!