Nissan Repair: AC problem on 1998 Nissan Quest XE, nissan quest, ac compressor

Question
Dear Sir,

My 1998 Nissan Quest XE has given me AC problems for the last 2 years.  I gave up to go to the dealer and/or repair station since they could not fix it completely.  Every time I came back, they just wanted to charge me more and more.  I decided to try to solve the problems myself.  I also learned more from your answers to various AC problems in this forum.  Here are what I found recently.  
1.  When the engine is hot, many times (not all the time) I was able to turn on the compressor by pressing or twisting a blue connector (High Pressure switch) on the back of the compressor.
2.  I checked the freon level on the low pressure site and it was fine (~45psi or boundary between blue and yellow mark on the gauge).
3.  Although the compressor runs, only the rear AC fan blows cold air.  The air coming from the front blower is not cold.  I touched the Accumulator Drier, it is warm/slightly hot, NOT COLD like in other car with good AC.  The Tee for Freon (where the low pressure plug is) indicates as follows:  The pipe goes to Accumulator is warm. The pipe that goes down to the rear line is COLD.  The small freon pipe that goes to the REAR AC is cold/sweating cold.
4.  Today I could not turn on the compressor by pressing the blue high pressure switch.  I then opened the relay boxes for the AC, FIDC, etc).  I was surprised when I pulled out the Relay marked FIDC, the compressor clicked and ran immediately.  I was able to turn on and off the compressor using the AC switch from the inside (dash board).  The compressor stopped if I installed back the FIDC relay (the color is blue with marked RELAY-1M, 12V, #25230     1B000, F6XA-14A436-AC).  Now the AC compressor runs normally (all the time) with the FIDC relay removed.  Do you know what is the effect of removing FIDC relay?  I drove the car around the blocks and it was fine.  However, only REAR AC gave Cold Air, NOT the Front since the accumulator canister was hot (not cold).
5. How to fix the accumulator (universal tank accumulator) so that it will be cold as in other car with working AC.
Please help.

Note that I took a picture of the freon lines and compressor, but was not able to attach it to this email.

Thank you in advance,
Jay G.  

Answer
Jay,

The computer for the airconditioner is screwed up and when you put the relay back in it is causing your problem with the internal control.  Now, this is only if you have the computerized climate control.  

Second, I think the reason your front system is not working is due to a blockage or a stuck expansion valve.  You can see this if you take the glovebox out of the passenger side and then remove the bottom cover under the dash.  You can feel the exaporator core and if it is hot you have found your problem.  Email me the photographs at vonsudderth@yahoo.com