Air Conditioner bypass

Hey guys. I would like to say hi and let you know that I am new to this forum and appreciate any help that I may get. I have wanted a taco for many years and happy that I just bought a '01 6 cyl. She's a beaut! Upon purchase tho did not second guess a toggle switch under the dash and thought that it was for fog lights. Just a few days after buying her I was playing with the switch going down the road and thought I noticed that I had more power going down the road with it switched off. Later a check engine light came on and my air conditioning stopped working! I freaked! Took it to Auto Zone and the code was for some general heat and air trouble. So they were little help there. Long story short the toggle switch was a by-pass for the air conditioner. There used to be a box mounted on the back side of the passengers fender. It is gone now and I noticed a wire running from the air conditioner to the toggle switch under my dash. Where the missing box (?) is there is now just a plug tapped off with a plug for it that is oval. This must be for the controls to turn the air on and off? And what is it called so I can look into getting it put back the way it was suppose to be. Auto Zone had no clue. One last thing, is it hurting anything with it continuously running on or off from the toggle switch? I think that is what set off my check engine light, but it has not done it since. Thanks for your help guys!! Rock on Yota lovers!

 

The plug and missing box is on the passenger side near the firewall. If I could get a part number from someone that would be great!