Jeep Cherokee Autodimming rear view mirror?

crdjeep

My rear view mirror is auto-dimming.There is a button on the left,and on the right of the mirror.When the auto-dimming feature is on the light on the left hand side lights up.But what about the light on the right,it doesn't do anything.Is it supposed to light up as well,I asked the chrysler service rep and he said the light should come on,so I said replace the bulb.I was told he can't because it is a sealed unit,therefore the entire mirror unit has to be replaced.Whats up with that??

tuggajb

the side that don,t ligh up is the senser that tell the mirror that you have bright lights behind you and auto dimms the mirror
full explanation in the service manual that you can get from jeep for about 100.00 bucks and explaines just about every thing that you need to know bout your jeep