So I ordered a few switches along with a new compressor, accumulator and a blue orfice tube. The switches are where I am confused based on a thread I read on here. The switches I got...
1.
http://www.oreillyauto.com/site/c/detail/MRY0/36674.oap?ck=Search_36674_-1_-1&keyword=36674

2.
http://www.oreillyauto.com/site/c/detail/MRY0/35974.oap?ck=Search_35974_-1_-1&keyword=35974

3.
http://www.oreillyauto.com/site/c/detail/MRY0/35756.oap?ck=Search_35756_-1_-1&keyword=35756

I believe #3 goes into the compressor. I have no clue where #2 goes. Are those switches pressures going to be good with r134a and do I have the switches going into the right location? I want to make sure this conversion is done right.

 

#1 is the low pressure switch, It goes on the accumulator, #2 is the high pressure switch which goes in the back of the compressor.

Take #3 back to the store and get your money back, It has no purpose for your application.

Yes, These pressure switches are fine for R12 or R134. Also, I found on my Buick DD putting a Ford blue orifice tube in didn't do diddly squat to cool better as claimed by many.

I keep a thermometer in my center vent, Had to replace high side line only. Added a blue orifice with the new line then recharged with same exact gauge pressures, Still blows same exact temps......

 

Thank you Sir.

 

I have used a Ford Red and a 98ish Seville orifice tube with pretty good sucess with R134a. Ford Blue will make the a/c about 2-3*F cooler at idle than white.

 

As I said, Made zero difference in temps in my Buick..... I don't see how it does in anything else.....

 

With the ~0.060" Cadillac orifice my Express cools to about 40-44*F at IDLE in 95-100*F weather with both front and rear units on high. Going down the road I have seen it hit 30*F. Gets cold enough to make your knuckles hurt. I have used the Red orifice which is .062" in multiple retrofits and they get equally cold. The smaller orifice raises the head pressure slightly but decreases the suction side pressure. Greater pressure drop = Colder temps.

http://www.cadillacforums.com/forums.../t-233758.html

Idle


Stationary @ 2,000 rpm

 

Heat exchange is the biggest key. You gotta pull air through the condensor to bring head temps down-the lower the better for the AC and the less wear on the compressor. Consider a bigger (CFM rating) electric fan if the stock one is not adequate.

 

Gonna throw a set of ls1 fans that I have on it.

 

^^^What he said.....Will let you install a smaller orifice to allow for a greater pressure differential without increasing your head pressure too high.

The setup I have above uses an aggressively pitched mechanical fan from a Duramax diesel truck but I was using dual electrics from a late model Tahoe until I burned one of the motors up.

 

At set of LS1 fans should certainly do the trick-they wire in series through 3 relays just like the LT1 fans did-I have harnesses available for them if you need one.

The typical method is to use 2 ground triggers to activate each speed-so one can be the ecm, the other can be off a switch and a 4th relay could be used as an AC override. Keep in mind if you wire any fan(s) to come on @ 100% speed, then off, etc. it will burn up the motors in short order-fan motors don't like the sudden arcing and inrush spiking in that manner of wiring. Cheap relays don't like it either since the contact material in lower grade relays don't have any Cadmium in the contact material-they usually have only Ag (silver) and maybe O (oxygen) which doesn't take heat as well-the better ones have Ni (nickel...very high heat rating 2600F!).So while all 5-pin Bosch style relays appear the same-they are not. Suffice it to say, if you find them on the parts store shelf on the floor, they're junk-if you end up buying them from behind the counter as an OEM relay, they are much better quality.

 

Also, try to avoid relays with Sn (Tin) -it embrittles metals but is cheap to manufacture-not a very good alloy material for relay contacts.