Except it is a 2013 F6B, not a 1500. The relays are labeled on the top of the relay box under the seat.Here is a picture of the relays and what they are for. This is from a 94 manual but I have a 2000 manual and it is the exact same. Relay #2 is for the stop lights. I would swap it with the #5 relay which is for the air pump.