It mite, The 5th is for a back up silinoid that blocks out your electric brakes. It works off of your back up lites. If the pins work out that the fifth pic misses the 4 pin block. I have seen 4 to 5 adaptors. Hope this helps. Rod
I need to amend my post. I stated Electric brakes, it is for surge brakes. The silinoid blockse the surge function from activating and applying the brakes when you back up. If you get a trailer with electric brakes, you will need a brake actuater that mounts in your cab. Sorry for the wrong info earlyer. Rod
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