# 1990 Toyota Corolla: override switch & a/c

**URL:** <https://community.cartalk.com/t/1990-toyota-corolla-override-switch-a-c/16985>\
**Category:** Maintenance/Repairs\
**Created:** [July 20, 2008, 10:01pm UTC](https://community.cartalk.com/t/1990-toyota-corolla-override-switch-a-c/16985 "2008-07-20T22:01:21Z")\
**Posts on this page:** 3\
**Page:** 1

<div class="post-metadata">

**Author:** ![GrampaGumbo](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/grampagumbo/32/391_2.png) [@GrampaGumbo](https://community.cartalk.com/u/GrampaGumbo)\
**Post date:** [July 20, 2008, 10:01pm UTC](https://community.cartalk.com/t/1990-toyota-corolla-override-switch-a-c/16985/1 "2008-07-20T22:01:21Z")

</div>

Suddenly, I cannot shift out of Park unless I depress the transmission override switch on my 1990 Corolla? Also, at the same time, my a/c is not cooling suddenly. Any correlation? or coincidence?  
  
 Any answer on the override switch problem?  
  
  
  
 Thanks,  
  
 GrampaGumbo

---

<div class="post-metadata">

**Author:** ![alex3324](https://avatars.discourse-cdn.com/v4/letter/a/8e8cbc/32.png) [@alex3324](https://community.cartalk.com/u/alex3324)\
**Post date:** [July 20, 2008, 10:16pm UTC](https://community.cartalk.com/t/1990-toyota-corolla-override-switch-a-c/16985/2 "2008-07-20T22:16:32Z")

</div>

I can’t think of any correlation between the A/C and the shift interlock. I can’t say for sure on a Corolla, but on many cars there is plunger that doesn’t allow the car to shift out of park unless the brake is applied. Is the override switch a mechanical switch or electrical?

Often, the interlock plunger gets gummed up with coke/cookies/ice cream etc. that’s spilled on the shifter, and on a 1990 model year car, there’s bound to be plenty of goodies down there.

Your first course of action should be to remove the shifter housing and clean out the shifter assy. Once you do that, test to make sure the switch is getting power when you press the brake pedal. Are your brake lights working, as this could be indicative of a faulty brake light switch. Lots of things to check.

---

<div class="post-metadata">

**Author:** ![GrampaGumbo](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/grampagumbo/32/391_2.png) [@GrampaGumbo](https://community.cartalk.com/u/GrampaGumbo)\
**Post date:** [July 21, 2008, 12:19pm UTC](https://community.cartalk.com/t/1990-toyota-corolla-override-switch-a-c/16985/3 "2008-07-21T12:19:39Z")

</div>

Thank you! I will check these things out. Much appreciated.