Help: AC/Heater problem

[VIPERMAN]

I have a 2000 RT/10 and I have never had any problems with the AC before.
This week when I took the car out I realized that I couldn't adjust the temperature of the air anymore. Air comes out, fan speed can be adjusted but the temperature controller (the one in the middle) seems to have no effect. The temperature is neither cold when I put it on cold neither hot when I put all the way hot so I guess my system is just bringing air from the outside ...
At the beginning I thought that may be I needed to refill the system with AC gaz but then that wouldn't justify why there is no hot air when I use the heater ?!
Any thoughts on why this is happening ... Could it be an easy fix like a specific internal fuse or something ?

 

[Hoosier Daddy]

AC has only one setting. COLD. That knob while you can adjust it is not functional in the AC mode.

 

[VIPERMAN]

Hoosier Daddy thanks for your input,
I am aware of what you said but that doesn't answer the question why on AC mode air is not cold and on heater mode air is not hot ...

 

[twinvipers]

My heater knob recently broke. You might want to adjust it manually under thre hood to see if that is the problem.

 

[Steve-Indy]

Look under the hood, on passenger side, at the back of the heater-fan shroud...where the visible small heater hoses lie...look to see that the wire loop at the end of the cable has become detached from the lever that opens/closes the heater...if this is OFF, just reattach the loop.

Please let us know what you find.

 

[Steve-Indy]

...AND, while you are looking at the above mentioned valve on heater, LOOK CAREFULLY at the 2 hoses leading in and out of the valve...be SURE that the 2 silver colored "crimp-on" hose clamps are holding the hoses properly/fully in place. These clamps (sorry, but I don't know the type name) are NOT the usual constant tension clamps that you find on the other ends of those hoses, and they can allow hose to creep off !!! This is especially important if you plan to track car ( aas noted by First Class Viper Tech and Viper Days Tech Inspector Mr. Tom Sessions !!! ). One can order proper size OEM constant tension clamp (you know...the kind with the sharp, long ears) or use a good quality standard hose clamp (preferably stainless steel with a stainless steel screw...Breeze is a source). I know that 1997 Vipers had the usual constant tension clamp here but that 1999-2002 had the new style...don't know about 1998. Good luck.

 

[VIPERMAN]

Steve-Indy and Twinvipers, Thank you for your help.
I went under the hood: the wire is perfectly connected to the lever and the 2 hoses are well in place so the problem is not there ...
I did notice something though: when I put the middle cursor on hot and put the right cursor to blow air on the windshield or on my feet the problem disappears (air comes out hot). But as soon as I change the right cursor to blow air from the dashboard vents air is not hot anymore and on AC mode air is coming out throught the dashboard vents but is not cold either ...
wierd

 

[Mike_W]

I was told that hot air only comes from the bottom, and cold air or outside air will come in from your vents on the dash.

I also noticed this the other day. I was driving with AC on, then I mashed the pedal down. Suddenly, my AC turns off and starts shooting out hot air. Not warm air, HOT air from the floor board, and underneath the dash.

I decided on my own that my car is turning off the AC to give me extra power. Is that right?

Mike

 

[VIPERMAN]

Mike,
If that's the case then there is probably nothing wrong with my AC and I just need to refill my system.
I don't know about AC turning to heater by itself to give more power.
Can anyone out there check this for us, I am really curious to know if heater's air ever comes out from the dashboard vents ...

 

[Steve-Indy]

TNT2000...thanks for the followup.

If one is cruising in Viper with A/C on (which generally but not always assumes hot ambient air temp), and then heavily accelerates (WOT), the A/C shuts off, but the vents/fan motor stay on, and hot air comes into cockpit , but this is ambient air by my understanding, and not "heater air". During WOT, the PCM (via TPS)"de-energizes the A/C compressor clutch relay". Others may have a better explanation, but I hope this helps until more post.

 

[VIPERMAN]

Thanks Steve,
Can you confirm that on heater mode, hot air won't come out from the dashboard vents but rather from the top or the bottom only ?

 

[Steve-Indy]

By my MEMORY, the dash vents blow air that feels hot as it is ambient air that follows cold flow...hope that makes sense.