Welcome to the forum John. Start with the easy stuff, take the 7-pin connector apart and clean out all the dust and dirt and look for corrosion. If that checks out and the wiring underneath the truck looks good the other usual suspect is the Solid State Relay (SSR). The SSR should be on a bracket in front of your fuel tank. See pictures in this thread:
If that doesn't set things right then you really need to get a bi-directional scan tool to see the body and chassis codes. There's 3 electronic parts to the ITBC but it also integrates with the BCM and EBCM. If you post up where you live maybe someone nearby has a Tech-2 that could pull the codes and tell you what's wrong.
PN# for the SSR is in that thread too.
Word of caution, we have seen some guys fry their system because they hooked up an aftermarket controller AND kept the factory setup connected.
You should try to get the code(s). Sometimes the auto parts stores have an advanced scan tool to read chassis and body codes, so it might be worth a few calls to see if they do.
Before I had a good scan tool I was able to go to a local Advance Auto to read the body codes for a friend's airbag light. Saved me a lot of time and searching, and I replaced the clockspring to fix it. The code will let you focus on the specific cause.