It would be helpful if you filled out your profile so folks know what model year you're talking about. The switches changed from 97-02 and 03-06, I'm going to assume that since you mention four switches you have an 03+. If that's the case, the 3rd switch from the left is for locking out overdrive if you have an automatic. 3rd from the right would be for the rear wiper if you have a hard top.
2006 Rubicon Unlimited Auto/Dual Tops
Mods: RB1 Navigation Radio, Cobra 75 CB, IPF E-code conversion, Rusty's steering box skid, Rusty's radiator skid
1988 Pontiac Fiero GT 5 speed
Work in progress...