1993 Grand marquis Heater control issue
Hi, New to the forum.... and I need some advice.
We bought this car new.... and have had few issues with it over the years but still love the car and want to keep it around for a while longer.
This happened last spring and now that it's cooling down I noticed it again.
The problem is the temperature control selector... We've had in on cold (in the far left position) all summer... this morning it was cold out so I moved it to the far right (HOT) .... after the car warmed up I tried to adjust the temp back down some but the temp stayed on HOT.... even if it's as far left as it will go.... AND the A/C is on.
So, could this be a vacuum issue?.... or maybe an actuator that's failed?
I'm just looking for a starting point and any advice would be greatly appreciated.
Thanks,
Don

 

it could be a vacuum leak (check the check valve under the hood that feeds vacuum to the vent system). it could be the blend door actuator. Generally if it's the vacuum issue, you'll loose vent control as well as temp control. It'll either drop to the floor or the defrost vents when hot. if it will stay on panel vents but remains hot, it's probably the blend door actuator. I'm not sure which setup the 93 has (wife has a 93 vic, but I've never had to get into that area on that car). If it's similar to the other lat model vehicles and has an electric actuator for the blend door... take a look at these two sites for some cheap repair options:

Here's one fix for if the blend door just flops end to end:
http://www.blenddoorfix.netfirms.com/

Here's one that covers a broken blend door as well:
http://www.conceptualedge.com/blend-door/

 

Slymer,
Man.. that sounds like it might be the problem. My wife drives the car more than me. I need to investigate further.
The links were very informative and will help.
I'll bet the Merc's and Ford's are the same... every part on our car has Ford on it anyway.
Thanks for the tip!

..... BTW Great site! Just found it today.

 

good luck. Let us know.