Best Wire Sleeve Parts for Cars, Trucks & SUVs A car or truck's electrical system is subject to the elements and liable to encounter moisture, dirt and heat over the lifetime of the vehicle. If a wire becomes damaged or torn, the vehicle could injure you and also need costly repairs.Dorman Black Wire Conduit · Dorman Split Wire Conduit Heat Shield And Wire Protection | JEGS Heat Shield and Wire Protection. Protect those wires with heat shield and wire protection from JEGS. Slide on wire heat shields are perfect for engine compartment wire looms especially on the engine. Flat heat shield material can be used to deflect heat away from areas like the inside of your car.