1991 AC quit blowing air through the dash vents

[Ohjai]

Took my wonderful ride out for some fish and chips, but the dash vents quit blowing any air.  Cold air is coming out of floor verts and the defroster vents on the windshield.

What do I have to do to get it blowing like it did a yesterday.

 

Jim

[Ronnie]

When the A/C programmer loses vacuum the default setting for the airflow is air coming  out of the defrost vents. Might a bad vacuum line? They tend to rot near the cruise control servo. Did the cruise stop working to?

 

Here are some places to check:

 

[Ohjai]

Thanks Ronnie.  I have a line that is just hanging loose, but I don't know where it connects.

[Ronnie]

I don't recognize what you are showing in the photos. Maybe something unique to a '90-'91 model?

 

However, I do see a bad vacuum hose connected to the fuel pressure regulator. (Blue arrow in photo below) That tells me more vacuum lines may be rotten and need replacing.

 

[Ohjai]

Good eye Ronnie.  I will fix that.  I will put it on my list to change all the vacuum lines.

 

I found my culprit.  The round connection I was holding in my hand, is one end of a broken vacuum T fitting.  Looks like about a 3/16 line feeding 2 1/8" lines.  I have some super glue curing now, hopefully my patch fix will work until I can get a real part.

 

I will put some pictures after I have the task completed.

 

 

[Ronnie]

Ok, now I think I know what it is. I didn't recognize it the way you were holding it. It's a Tee but it's also a check valve so don't replace it with just a plain Tee fitting. Glad you found the problem.

 

[Ohjai]

Thanks Ronnie.  I have it fixed.  I will try and find the part in the parts book and get a new one.  But in the meantime I fixed this one and the AC is working properly.

 

[Ronnie]

Your looks a little different from what I thought but it's probably also a check valve. Glad you got it working.