Trying to hunt down control module 15832319 to fix the rear heat in an 05 escalade. Every after market source I've tried is out of stock or back ordered. This includes gmparts direct and a couple of the amazon sources. The dealer claims it shows as available but is 180.00 vs around 75-80 elsewhere. Anyone have any other sources to try before I just get it through the dealer? With this arctic blast and kids I'd like to get it fixed soon.