joined to thank boatbuilder (as well as the person who posted the pics of the process) for the specific instructions regarding replacement of the thermo control amp.  have a 2000 Xterra that was having the intermittent A/C issue.  It was accompanied by a squealing belt when the A/C would kick on.  I thought the belt might be the issue, so I replaced it.  No help.  Since the A/C would blow very cold air at times, I thought the blower and compressor must be functioning properly - at least some of the time.  I was hesitant to take it to a mechanic - much less a dealer.  When I did some internet research, I quickly came across this thread.  I went to the dealer and bought the part ($60 with tax).  I printed Boatbuilder's instructions and went to work.  31 minutes later, I had STEADY cool air.

thanks again for all the great info.  you saved me a bundle in "diagnostic" charges and probably a new compressor, charge, hose replacement, etc...

Cajun59 wrote: Has anyone tried simply to bypass this "TCA" vs replacement.

..

I have a 2000 Nissan Frontier Crew Cab with 196,000 miles with the same type a/c problem.  The problem started last summer.  I took it to a local repair shop.  They said they could not find a problem and filled it with dye to help check for leaks.  They said it was low on freon and "refilled" it.  It still does not work.

With our Texas summer tempatures remaining around 105 degrees for the last week I have really noticed the a/c issues.

I am going tomorrow to get a TCA and replace it.  To make things worse my window switch for the drivers window also stopped working.  Any suggestions on fixing this? 

I picked up a TCA this morning from Nissan dealer ($40.40).  The parts worker stated they had the same issue with their parts delivery frontier truck.   After they made the same repair they have not had any problems.

It took me about 30 - 45 minutes to make the repair.  The A/C is working GREAT.  Thanks Boatbuilder and everyone else. 

As I was serching the web I did see the TCA for $29.00; however, I could not wait its hot here.  If you have time to order one, you might want to look around and save a buck or two.

Thanks again.

Hey Birds,

I changed my TCA on Saturday, June 18th.  It has worked great ever since.  I had to turn my AC down today, June 21st, because it got too cool.  What a nice problem!!

I followed the instructions above and the suggestion of using the chopsticks to get it installed.  You might try using forcepts (I use these to remove the hooks from fish when I go fishing) to help install it.  They will allow you to hold it easier while installing it.  Take your time and Be patient and you can get it installed.

I did not have to "recharge" the system or even touch any other part of the AC.  The pictures on Page 2 of this forum give you an idea of what it will look like.  I am handy, but I am NOT a mechanic.  If you know how to use a screw driver and can follow directions you can install it.

The TCA plug was attached to the housing.  Unless the freon runs through the wiring it will not cause it to leak.  As I said, I am not a mechanic but I do know that the freon does not run through the wires!!  It has been 4 days since I installed mine and it continues to work extremely well.

Good luck.