One of two things happens on these trucks, first is the switch goes out and the next is the encoder (actuator) goes out both cause the light to come on. I would try the switch first.
Here is a wiring diagram of the system and a guide to help you confirm the failure:
Here is a guide to help you check the wiring:
You should check the fuses as well.
Check out the diagrams (below).
Please let us know what you find.
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Sunday, December 3rd, 2017 AT 1:11 PM