Here's a little makeover of an inexpensive aftermarket car seat heating pad that stopped working.
Designed to activate and warm up when sat upon, the electronics face a fair amount of abuse: since the seat is a soft frame, the wires inside constantly move and flex with the body. They are also subject to harsh temperature changes with frequent (very) cold weather heating and cooling cycles, adding to a situation ripe for a malfunction, which happened to one of our staff when he couldn't warm up his tush one cold Canadian morning...
Dragging it into the lab, we peeled back the covers to discover the usual and not-so-usual suspects.
The old wires had a PVC jacket that had dried out and cracked.
The wires would then flex at these cracks and break:
We replaced those wires with our GroovyNoodle silicone wire, which is able to resist flexing and temperature fluctuations very well.
Here's a picture of the sketchy activation switch we found inside the bottom part of the seat. It's designed to close when under "bum load", and directly pass power to the heating coils. We're not experts at auto-grade accessory manufacturing, but we were surprised that it wasn't a logic "bum-detected" switch that triggered a suitable relay or FET elsewhere. And the lack of a thermal reset fuse surprised us.
All broken wires replaced! Almost all the PVC jacket wire had cracked and disintegrated, so we replaced it with our better-quality GroovyNoodle silicone wire. This wire is extremely flexible, high strand count, and a temperature-ignoring silicon jacket. Perfect for inside this car seat heater.
All necessary repairs and upgrades were done just in time for the next stretch of (very much) cold Canadian winter.