99 T & C Air conditioning problem

The AC on my '99 T & C, with rear air, after seven years of excellent
service has finally developed a problem. System stopped cooling at
the beginning of the summer. Took it to a non dealer service center
and they evacuated and recharged. Worked fine for two months then
gradually stopped cooling.

So Im assuming it has a system leak.

How do you go about locating the leak?
If it is one of the major components that is leaking, would a scan
tool diagnose the problem? Does the HVAC system have its own computer?

Frank

 

A good repair shop can check for proper feron charge and run a leak
test and find the leak.
Some scan tool will pick up low freon.
But the proper way ia a pressure gauge test on low and high side with
these.

http://tinyurl.com/jt94c

http://tinyurl.com/qvn5k

http://tinyurl.com/q2h9j

 

The best way to locate all leaks is by doing a dye test. More the likely the
evaporator is what is leaking, a common problem for this vehicle

Glenn Beasley
Chrysler Tech

 

Thanks

I'm assuming there are two evaporators with rear air. Is the front
the most likely to be at fault? And can the dye check detect it
without exposing it or is it process of elimination if no other leaks
are detected? I'm led to believe it is hard to get to, therefore
expensive to change out.

Frank

 

Correct assumptions all.

 

Due to debris such as leaves and other trash falling into the cowl and
entering the heater box the front evaporator normally fails. The rear evap
is not exposed to these elements.
A dye test is used to basically check all outside fittings and components.
The front evaporator is under the dash and in order to see if it is where
the leak is coming from you would need to use the special lite to look at
the a/c drain for signs of dye.
Alot of times this will not show up and the evap fin temperature sensor
will need to be removed to get a peek into the housing where the evap
sits. Make sure if you use this dye you dont forget to check the condensor
for leaks

Glenn Beasley
Chrysler Tech

 

On my old 1994 GC, there was a small leak in the A/C system. My shop
put an additive into the system which will plug small leaks. It worked
like a charm! We figure the leak was in the condesor (under the
dash!$$$), but after adding the stop leak to the system, all was well.

That was done over 3 years ago and the A/C was still working just fine
when the van was totalled in an accident.

 

For clarification, the condenser is in front of the radiator under the hood.
The evaporator, as noted in previous email in this thread, is located inside
the passenger compartment under the dash. One is fairly simple to replace
while the other is a PITA.

Bob

 

or can look at a known problem area yourself
open glove box and drop it down out of the way you will see a black rubber plug in the
side of a black plastic case pull it outward with out damaging wire and look inside hole
with a bright lite if you see a black like oil film on the bottom of the evap coil then
your evap is no good and leaking
there is also issues with rear ac./heat systems leaking at the rear connections and pipes
again oil film show up easily

 

My Bad.

Thanks Bob.

 

dropped the glove box and see the plug, trapezoid shaped, has an
electrical connection fixed to the outside of the plug. Can the
connection be disconnected to take a look and then reconnected without
any issues? plug will not come out far enough with it connected and I
don't want to dislodge or damage the wiring or sensor. With it
disconnected it appears the plug will pivot down and the sensor side
wiring will not be stressed. I can tell from cracking it open that
the evaporator is back there but can't get a good look at the
bottom.

Frank

 

careful; do what yuou have to to get it out

 

Did the shop who did the recharge check for leaks prior to their work? I
believe they are required to in most areas.

The source of a leak can be difficult to find, and small slow leaks - like
you may be desribing - are especially difficult. But before you begin
tearing things apart, you should seek professional help.

My experience with this generation minivan would have me looking more
closely at o-ring seals and the compressor's main seal. Both tend to dry
out and leak with age. Depending on how you use your system, infrequent use
could be your biggest culprit.

Where you live (you didn't say, right?) also can introduce other issues.
Tree leaves, etc, as indicated by others posting replies, can be an issue.
Driving a lot on gravel roads can toss rocks at the lines running to the
rear unit and cause punctures.

My advice remains the same: seek professional help. A good shop will
quickly locate the leak and explain your options.

My 2 cents.