99 sport towing hookup.

[biggiesize]

I'm installing the trailer hookup on my 99 sport. I have an adapter on the passenger side that has a black cover and I have a similar-looking adapter on the driver side with a gray cover which one do I use for the towing adapter?

 

[J_C]

As far as I know the stock towing package adapter harness is on the left side, so if there is one on the right side, it could be that a prior owner added it. Does it use the same connector and # of pins in it?

If that's the case then the question becomes do you need more than the stock connector features and/or what plug do you have that fits either?