Common Problem Help?

[RangerFella]

Alright, so, this seems to be a common problem with Ford vehicles - not just trucks. I had a 97 escort do the same thing. Two of my friends' F-Series are also plagued by the same issue.

I turn on my AC, or heat, in my 97 Ranger (info over there <--), and sometimes it will come out of where it's set to come out, and other times it will just randomly click over to the Defrost vents (behind the windshield, on the top of the dash). All the time, only the middle two vents work. Neither of the outer most vents on the front of the dash work. You can feel just a TINY bit coming out but it's so little that it's better to just close it to make the only two working ones blow harder.

I've noticed it more with the AC than I have the heat, for whatever that's worth. I usually fix it by switching the knob from 9 o'clock to 3 o'clock several times rapidly. If that doesn't work, I just have to wait for it to decide to start blowing out of the vent it's set to come out of.

So, how do I fix this? Difficulty level? Do I need to remove the whole dash to do it? If so, how much would I be looking at to have a shop do it?


Thanks for your help in advance!

-R

 

[RangerFella]

Anybody?

 

[RangerFella]

Come on man...somebody's GOTTA know this one.

 

[Earl43P]

That's probably a vaccum problem.

Inspect the vaccum tube from the vaccum tree to the torpedo shaped or spherical black plastic reservoir. Then inspect the other tube going into the firewall from the reservoir.

If you don't find a leak, burned spot, or crack in that tubing, report back.

The problem could also be elsewhere in the vaccum tubing, so inspect alll the others in the engine bay too. There should be a vac diagram on your radiator support.

Don't forget the PCV and brake booster tubing.

 

[RangerFella]

Alright, 'torpedo shaped reservoir'

Surely you don't mean the air filter housing. I didn't see anything like that on mine but maybe I missed it. Where is it, approximately?

Also, thank you very much for the reply. Someone did tell me yesterday that the 'valve' is controlled by a vacuum system so, I can assume, that would make sense.