# 1989 MB 300SEL Air Conditioner

**URL:** <https://community.cartalk.com/t/1989-mb-300sel-air-conditioner/31627>\
**Category:** Maintenance/Repairs\
**Created:** [June 9, 2009, 10:06am UTC](https://community.cartalk.com/t/1989-mb-300sel-air-conditioner/31627 "2009-06-09T10:06:50Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![mint1989](https://avatars.discourse-cdn.com/v4/letter/m/c89c15/32.png) [@mint1989](https://community.cartalk.com/u/mint1989)\
**Post date:** [June 9, 2009, 10:06am UTC](https://community.cartalk.com/t/1989-mb-300sel-air-conditioner/31627/1 "2009-06-09T10:06:50Z")

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It will work perfectly for about 30 minutes or so and then will just blow air. The temporary fix is to turn the car off, restart and it will once again work perfectly and then resume to just blowing air.  
  
  
  
 Any clue as to what the problem is?

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**Author:** ![BustedKnuckles](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/bustedknuckles/32/25_2.png) [@BustedKnuckles](https://community.cartalk.com/u/BustedKnuckles)\
**Post date:** [June 9, 2009, 10:23am UTC](https://community.cartalk.com/t/1989-mb-300sel-air-conditioner/31627/2 "2009-06-09T10:23:04Z")

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Have the system checked for proper pressures at the service ports. Typically, for this age, a small leak may have developed, and the system is low on refrigerant.

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**Author:** ![Cal\_Learner](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/cal_learner/32/387_2.png) [@Cal\_Learner](https://community.cartalk.com/u/Cal_Learner)\
**Post date:** [June 9, 2009, 10:36am UTC](https://community.cartalk.com/t/1989-mb-300sel-air-conditioner/31627/3 "2009-06-09T10:36:29Z")

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Low refrigerant is a good bet. Also have your mechanic check the compressor relay and the low pressure switch on the A/C drier, both of which control the operation of the compressor.

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**Author:** ![texases](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/texases/32/862_2.png) [@texases](https://community.cartalk.com/u/texases)\
**Post date:** [June 9, 2009, 1:40pm UTC](https://community.cartalk.com/t/1989-mb-300sel-air-conditioner/31627/4 "2009-06-09T13:40:30Z")

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Have you found a good independent MB mechanic? Older MBs are known to have weak AC, you need somebody familliar with it to get the most out of it.