This isn't the best way to tell if it's working; my light is burn out, but the switch is still functional. Tested with a multimeter.

 

Generally, the switches fail internally either blowing the fuse or shorting. Best thing to check is teh 7.5 amp "trans" fuse that powers that switch.

 

The light switch work, but if i unplug it, it work ever in comfort mode?

Regards.

 

Yes, it will be permanently in Comfort mode.

 

Leave it in sport. Firmer shifts are easier on the clutches. A softer shift allows the clutches to slip as they engage, thus wearing the clutches faster.

 

I agree with you.

 

Does anyone know if it's true about getting better mpg in power mode?

 

Yep. I get 5 mpg in comfort mode 9 in power. Lol

 

I mostly drive my '91 XJ on a daily newspaper route and I tried it in both positions several times and "I" get better mileage in the comfort position. Next week after I give this route up and go to work in the woods fulltime, I'll try it again and see what happens.

 

Also if i unplug the 7.5 amps fuse for the trans, i'll ever be in comfort mode?

 

It doesn't hurt mileage and probably helps. That's why Jeep eliminated the switch in 91 or so and just left the tCU in the Power mode.

 

Yes. And your reverse lights will not work anymore.