gunrunnerjohn posted:What's a PPTC?
Seriously, the PTC is wired between the two rollers on the car. The purpose is simply to protect the wiring in case the car derails and one roller lands on an outside rail.
https://www.ebay.com/itm/10PCS...e-Fuse-/232141302070
10PCS RXEF025 XF025 72V 0.25A 250MA PPTC Resettable Fuse