zaitsev44

Hello y'all, I've been a lurker for a little while, but finally had a need to make an account and post a question. I bought a 2014 GMC Sierra 1500 last month and have had the usual "new to you" bug fixes. Anyway, I have had an issue the past week with the temperature gauge either not moving from start-up or dropping to the bottom in the middle of a trip. Once it shows the needle at the bottom, the cooling fan kicks into high gear and won't turn off (even after the ignition is turned off) until either I unhook the battery terminal (doing this keeps it from happening for at least a day or two) or, if it is cold enough outside (<40*), it will turn off on its own about 3 minutes after the engine is turned off. Coolant level and #12 and 13 fuses are fine as well. I ordered two new relays, but cannot find where the cooling fan relay is located. Anyone have any idea on straightening this out? Thanks!