Nissan Repair: Wierd A/C Problem, 2000 nissan exterra, receiver dryer

Question
Von,
 I have a 2000 nissan exterra with the 6 cylinder and I am having A/C problems, I am mechanicly inclined alittle. My A/C works according to outside temp., If there is an overcast and not real hot it works fine, when it is real hot it blows ambient air. I have found a leak on my discharge line and changed it out, so I am not leaking anymore, I had someone look at it and they said my compressor is bad but I don't believe it, I know I have to change the drier and expansion valve because I have tore into the system when I changed the disch. line, I was wondering if it could be the ambiant sensor on the dryer causing this.
   Thank you for your time.

Answer
Shane,

If you have replaced the leaky line and you have a new receiver dryer on the system and the expansion valve you should be fine.  Did you vacuum the system after you changed the parts?  You will have to vacuum the system first and then put the recommended charge in as indicated on the vehicle sticker.  If you have done all these things you should be fine.  Check the pressures and be sure to not put too much R-134 in the system as it messes up the temperature with too much.  I would not think the pressure sensor on the dryer would cause this.  All it does is cycle the compressor and if there is too much or too little refrigerant it will not allow the compressor to come on.