Posted: May 02 2008 at 8:51am | IP Logged

..

praetorianpi;

Welcome to the group.

... On the hot days does it blow cold air for a few minutes first and then start to blow warm air?

Posted: May 08 2008 at 6:48pm | IP Logged

I own a 2000 Frontier Crewcab SE w/ the 3.3 engine. I have had ac problems from the 1st year & every year (01,02,03,) they replaced the l.p. line. After warrenty, I had the same line (because of leak) replaced in late 05. The ac stopped yesterday. It runs cool for a few minutes & then goes to warm & shifts back & forth from cool (not cold) to warm. I took it to a shop & it is running a steady 80 on the low side & hi side varies & goes up to about 250 then the compressor shuts down. It will not take any more freon (dealer says). They said they think the expansion valve is clogging & that only happens when the compressor starts to go out. They want $1500 for the whole job. It was working good 1 month ago and there are no signs of a leak. It has 99,000 miles on it and I live in Fort Mohave, AZ (aka Hell)

Could the evporative coil be clogged? I live in a high dust area and often dust (i.e. sand) blows into my eyes when it's been off for a while

Posted: May 09 2008 at 11:09am | IP Logged

Checked some old forums, found this info. I'm going to try these today.

#1

You may want to do some research on a part called a “thermal control amplifier” This is a small electrical part that is located behind the glove box stuck in the evaporator coils.  It tells the computer if the system freezes up.  If this part malfunctions like mine did it will be cooling fine one minute and blowing hot the next. The TCA turns off the compressor so when it stops cooling check that first.  Replacement part at Nissan $45 and if you get in the floor and look behind the glove box you can see the little white three pin connector. 

#2

I had this problem with my 98 Frontier.  The A/C would blow hot once in awhile for no apparent reason.   I replaced the Thermal Control Amplifier.   $40.00 part.  and it fixed the problem.

#3

I'm having the EXACT problem with my 2001 SC extended cab. Exact! See my thread posted last week. I have had it charged and leak checked but the technician had no answers for the problem.

I was looking at a dumb Haynes manual that doesn’t even cover my SC truck but I noticed in the AC trouble shooting section it tells you to unplug the high pressure switch, located on the dryer canister at the top left of the radiator, and jumper it with a wire and if the compressor kicks on when jumped. The system is either low on Freon or over filled (read high pressure) or there’s a bad plug or sensor.

Here's the crazy part. I was expecting a two wire plug but when I unplugged it to run the check it was a 4 wire plug. So I was like "great" because I now don’t know what wires to "jumper". I decided to play it smart and just wait. My luck I'd jumper the wrong wires together and melt the whole truck down. So, I just plugged it back in. Now here’s the crazy part. I have driven the truck and parked in the sun and went in stores and whatnot (the things that usually caused it to not work) and it has worked flawlessly ever since. That was last week and It hasn't messed up since.

The truck was completely off when I did this. So I'm guessing it was some short or corrosion in that plug or something. I don’t know what I did or if it was just a fluke but my problem is seemingly gone (knock on wood).

Maybe you (original poster) should try it. It's easy and it can’t hurt. Just locate the dryer can and with the motor off unplug the plug and clean it and inspect it and plug it back in. Maybe you'll get lucky.

I have deliberately driven in the hot Texas heat and parked in the sun and waited two mins, then 5 mins , then 30 mins, then 1 hour and turning it off and on to try and make it happen but the AC is staying on  now and it works great.

I can’t imagine what unplugging that plug and plugging it back in with the truck turned off could have done. I just know my problem has been gone since.

I wish I could provide a rock solid solution because this may just be a coincidence. I just know I was having the EXACT same trouble you described and it was progressively getting worse in the July and August heat.  I only did what I described and the gremlin is gone.

Hope this helps,

Posted: May 11 2008 at 10:29am | IP Logged

Thank you so much to all of you who took the time to reply to my question. I am gong to try the TCA and will let you know how it went...

Sincerely,

Gus PraetorianPi

Nissan Frontier 2K 4 door V6 (still love the thing) 

Posted: Jun 21 2008 at 9:57pm | IP Logged

Hello everybody,

It is done, I replaced the TCA about 3 weeks ago, and the A/C is working great.  I have left the truck in the sun all day. Started the truck and "Voila"  cold air blows out.  The part was about $50.00 here in Orlando, Fl. and it just took me about 20 minites to replace.  Better than new......

Take care you all......

Gus PraetorianPi

Nissan Frontier 2K 4 door V6