S14 AC install in s13 - Complete - Install notes

[joe_nismo]

While there are some r134a s13 components, they are hard to find. So I went with a 95 s14 setup. This was a USDM s14 95-96 setup installed into a USDM s13 early 93 that had r12 AC previously before the SR swap.

My image links don't seem to be loading, so here's my imgur post of pics: https://imgur.com/gallery/Fjnz6M1

I found someone selling everything except the evaporator and compressor on eBay.



The biggest hurdle was fitting the condenser. The s14 condenser is rectangle double pass, while the s13 is a V shaped single pass. So the s14 condenser doesn't fit in the cavity on the lower half. I made a crude mounting plate with some steel from tractor supply store and moved everything towards the engine by about 1 inch. I mounted it on the frame supports that connect to the radiator support using existing holes.







The s13 evaporator had the same fittings as the s14 so no issues there. And my car still had the evaporator from before.



The s14 pressure switch is a 4 wire and measures low, normal, high I guess, so I went with the s13 binary so it would connect to my harness. The s13 switch only checks for min pressure. The fitting for the sensor is the same for the dryer so it screwed right into the reman s14 dryer.

I used a reman compressor for an s14 with a bracket from 240sxmotoring to adapt it to the red top SR. Belt came with the bracket and all hardware. You have to grind/cut off two nubs on the sr bracket for this adapter to work. I used a cutting wheel and angle grinder



I was missing the SR idler tensioner pulley that mounts to the SR AC bracket. Turns out it's the same part number as the GTR's AC idler pulley (pictured).



The climate controls didn't work at first, but after reseating all the connectors, it came alive.

Now that everything was hooked up, bolted, and fresh O-rings installed, I needed to pull a deep vac on the system to remove any air and moisture. I used loaner tools from Autozone for this step. OEM brand AC manifold and lines and an AC vac pump.



Pulled a vacuum for 1min on the low side. Closed the low side valve and waited 30mins. Vacuum stayed at 30 so I knew I didn't have an obvious leak anywhere. Turned the vac pump back on and pulled a vacuum for 30mins. This won't suck out any pag oil so don't worry about that. My reman compressor came prefilled too so no oil was involved on my end.

After I pulled a 30min vacuum, I closed the valve and disconnected the pump.

Time to fill it with r134a. I connected my first bottle and used the service line bleeder to fill the line with Freon. Then I started the car, turned on the AC, and opened the valve...nothing happened. Quick google and turns out I needed to jump the pressure switch at first since the system was completely empty. Duh.. after jumping the switch the AC compressor came on and started taking r134a slowly. I tried to keep the bottles warm with engine heat as they get ice cold when filling, the warmer the easier it is. Just like a bottle warmer on nitrous Holding the throttle pulley to idle up helped too. Took about 20mins for one can. Then another 20mins for the other. 650 ish grams later and she was blowing ice cold air out the vents for the first time since 2007.




Rough estimate of cost: S14 used lines and condenser $300 S14 reman compressor $400
S13 pressure switch $25
S14 to SR bracket $140
R134a $30 (Walmart had cans for $10 without any extra nonsense. Just Freon. No leak stop or dye)
Steel plate from TSC $28
GTR/SR pulley $50
O-ring kit $12
14 inch elec fan, installed as a pusher $25
Loaner tools $300 - but I got that back when I returned them

Note: I replaced my crunchy engine harness during this process with an oem one from wiring specialties.