I don't know anything about low temp problem with either unit, but I know wiring connections can sometimes be affected by temperature changes, especially with older wiring. Saw this fairly often in the Air Force. The first thing I would do is inspect both sides of all connectors to make sure there aren't any pushed pins or other apparent barriers to good connections. Next would be the wiring itself. But considering how complicated that could get, I'd wait for an answer as to whether or not there are any historical problems with temperature sensitivity in these units before digging into wiring. If there are pre-made harnesses made for your setup, getting a new one might be an option. Not the cheapest solution, but after all the time I spent chasing down elusive wiring problems over the years, the expense wouldn't bother me much.
