# intresting AC issues with 92 XE



## jakejj (Jul 3, 2011)

Bought a 92 Sentra XE model with only, get this,,, 88300 miles.. yes under 90K. Was kinda worried about motor being slugged up as the owner was now elderly gentleman that had bought the car new at local dealership. 

Engine looked good with some normal amount of oil looking stuff on it.. Opened the oil fill cap to look inside and was astonished to see a almost new interior of engine.. Cams looked new with slight discoloration on the interior under valve cover..

checked AC when buying and took on test drive was working fine.. now it wants to work some days and other day not.. Checked freon both in sight glass, good, and actual pressures.. at idle the suction is 28 - 30 PSi.. 

some days it will start running and just click compressor off for no reason.. then it will not engage compressor till next day or several days..

fan keeps going no problem all speeds.

check the relay near battery, actually switched it with another one and that component works just fine. 

I have search this and other forums with little luck on this issue..

downloaded the manual here,, nice thanks.. and see a dual pressure switch on sight glass /dryer and a thermal protector on the compressor.. 

any ideas.. 

:newbie:


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## smj999smj (Jan 1, 2006)

Low side readings literally only give you half of the story. To properly test the system, you'll need high and low side pressure gauges and follow the performance test procedure listed under the heating and air conditioning section in the FSM. Being a 92, it would have came from the factory with R-12. Most of the R-12 systems have been converted over to R-134a, or filled with a replacement freon like Freeze-12. This may affect your readings slightly.


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## jakejj (Jul 3, 2011)

*ac issues*

the system is still r-12. not converted or filled with freeze 12 , the issue is not what type of freon being used but what control or sensor in system is not working properly or working intermittently..

the system when working is blowing COLD air. it when it not working that a problem. 

there is something going on with a sensor somewhere I am not able to find or know about.

maybe someone with Nissan experience will chim in here and help me out.

:lame:


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## jakejj (Jul 3, 2011)

*think i found the problem,*

in searching around i found a thread about a [27675X] AMPLIFIER-THERMO
part that can cause trouble like i and others were having.

looks like this might be the trick.. seem to be a popular problem on these cars based on amount of stuff i was reading.

so thanks for the help? :loser:


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## jakejj (Jul 3, 2011)

*UPDATE ON PROBLEM,,, Fixed*

Went out today and pulled the glove box off to start looking for Thermo Control stuff to see what was going on with it..

The stuff on downloaded manuals pictures did not look anything like what i had under the dash. I found what i through was TC unit and started to trouble shoot. 

There was a plug that was attached to box looking thing that was attached to side of evap box.. I could see a circuit panel and proceeded to pull it apart.

Upon examining the board i noticed the plug, A three wire type, was loose, as in the solder joints were loose.. I reattached plug, cranked car, and tried AC. I was able to move plug up and down and the AC would cycle off and on when i did that. I could see the problem and devised a way to fix it. 

One was to re-solder the joints.. but no solder iron. The plug was screwed down to board with two screws.. I folded up some paper and inserted under plug and then re screwed back to board. 

it now works like a charm. The wire from plug was a bit tight so i pulled some slack. I suspect over time it the joints worked loose from driving bumps etc and would make contact some time and not at others.

I will try to attach pictures of what i did.










This show the box with plug on evap box,, glove box and support stuff removed. the two little wire go down under bottom and up to inside box.. 
the numbers on the plug holder are 48620-65820 not sure if that is part number or not.. it not a number i have been getting when searching for this part. 









This show the plug and how loose it was.. The three tangs are down through board and soldered.. 









Here shows the plug down before i inserted folded up paper and it screwed back down on board pulling plug tangs up making connection to AC circuit.. all is good now 

:givebeer:


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