# speedometer/transmission/AC problem **URL:** \ **Category:** Maintenance/Repairs\ **Tags:** chrysler, sebring\ **Created:** [August 21, 2009, 1:06pm UTC](https://community.cartalk.com/t/speedometer-transmission-ac-problem/35364 "2009-08-21T13:06:38Z")\ **Posts on this page:** 3\ **Page:** 1
**Author:** ![mdetke](https://avatars.discourse-cdn.com/v4/letter/m/838e76/32.png) [@mdetke](https://community.cartalk.com/u/mdetke)\ **Post date:** [August 21, 2009, 1:06pm UTC](https://community.cartalk.com/t/speedometer-transmission-ac-problem/35364/1 "2009-08-21T13:06:38Z")
Once every few minutes, when I’m driving at a steady speed my car’s speedometer drops to almost zero for less than a second, and then bounces back up. _Sometimes_ it hesitates or clunks, like the transmission (automatic) downshifted momentarily. It only does all of this when the AC is on. I’ve had it to 3 mechanics, a total of 7 times, with no success. ---
**Author:** ![transman618](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/transman618/32/24_2.png) [@transman618](https://community.cartalk.com/u/transman618)\ **Post date:** [August 21, 2009, 5:19pm UTC](https://community.cartalk.com/t/speedometer-transmission-ac-problem/35364/2 "2009-08-21T17:19:41Z")
Have they looked into the output speed sensor and its wiring?? transman ---
**Author:** ![mdetke](https://avatars.discourse-cdn.com/v4/letter/m/838e76/32.png) [@mdetke](https://community.cartalk.com/u/mdetke)\ **Post date:** [August 24, 2009, 1:15pm UTC](https://community.cartalk.com/t/speedometer-transmission-ac-problem/35364/3 "2009-08-24T13:15:47Z")
My mechanic says he replaced the output speed sensor and checked the wiring from the sensor to the transmission control module (repeatedly). The previous two couldn’t find problems with these either, and the Chrysler tech line couldn’t find any problems with the vehicle either.