strang3majik Posted February 24, 2009 Report Share Posted February 24, 2009 (edited) Not sure where this should go...so...its just plain ol' BS for now...lol But, when I got my car, everything under the hood AC related has been removed...relays, lines, fan, condenser, everything. Even the beauty of a cut wiring harness. Now, before the hot season starts again here in FL, Id like to get it all working since the Quest is my daily. But...I have an 87...and I have an 88 parts car with all the parts lacking the compressor. My questions are, if I were to switch to the 88 harness, what problems would I encounter. (knock box, MAS...) anything else? Or would it be a better idea just to splice wires back in? What parts can I reuse? And which should be bought new? And, lastly, what must be done to run R134? Thanks guys...this will be a project Im sure, but...it must be done. Black Quest, black leather interior, sunroof, in sunny FL...you do the math Edited February 24, 2009 by strang3majik Link to comment Share on other sites More sharing options...
Fanta Posted February 24, 2009 Report Share Posted February 24, 2009 you also ened the ECU for the 88 harness Link to comment Share on other sites More sharing options...
strang3majik Posted February 24, 2009 Author Report Share Posted February 24, 2009 you also ened the ECU for the 88 harness Mines already got the 88 ECU...but, the engine harness goes inside??? Thats not cool. Up at the front of the car...there wires hanging with tape over the ends that went to the vac pump, condensor???, compressor??? Link to comment Share on other sites More sharing options...
vbrad511 Posted February 24, 2009 Report Share Posted February 24, 2009 Swapping the 88 harness might not be needed to run the AC. I was in the same situation with my 88 when I bought it. Things had been removed all the way back to the firewall. I got lucky enough to find the AC wiring had been cut behind the front bumper. I was able to open the taped up mess and splice in the appropriate wires from my parts car. Of course I had the motor and trans out when I put the lower lines in place, that made it easier. I'd bet your wiring's the same way mine was. I did change all the orings I could get to while it was apart. Do that, and then just get the 134 conversion kit. Piece of cake. Link to comment Share on other sites More sharing options...
Starwolf Posted February 24, 2009 Report Share Posted February 24, 2009 Where can you get the 134 conversion kit and how much does it cost? I am also needing a bit of info on this Link to comment Share on other sites More sharing options...
vbrad511 Posted February 24, 2009 Report Share Posted February 24, 2009 Where can you get the 134 conversion kit and how much does it cost? I am also needing a bit of info on this Used to be about $35 at most auto parts stores. I haven't needed one in years, so I don't know nowadays. They used to come with two fittings to screw over your existing R12 fittings, a can of some conditioning oil, and the 134. You also don't use as much 134 as you would've if you'd used the R12. There's a percentage ratio, but not hard to figure out. Link to comment Share on other sites More sharing options...
strang3majik Posted February 24, 2009 Author Report Share Posted February 24, 2009 any idea if using a used compressor and drier is an okay thing to do? Link to comment Share on other sites More sharing options...
vbrad511 Posted February 24, 2009 Report Share Posted February 24, 2009 If the compressor still spins with some resistance I'd think it was ok. Get a new dryer though. Probably $20 max. That's assuming the system's been sitting open. I might even change the dryer if I was converting. What I've done has worked for me so far, but somebody more knowledgeable will certainly chime in on this. Link to comment Share on other sites More sharing options...
strang3majik Posted February 24, 2009 Author Report Share Posted February 24, 2009 (edited) cool...thanks man. I hope you're willing to answer any questions I may have for you about doing this but does anyone really know anymore about the harness swap? It would just be nice to have all solid wires if possible...spliced wires in the engine compartment aren't very desireable to me...though, if its a huge issue, then, nevermind. But, I already have an 88 ECU, I want the 88-9 knock box eventually, and am going to a 1G MAS anyway, so....any other things that would be different that would cause headaches between years? Edited February 24, 2009 by strang3majik Link to comment Share on other sites More sharing options...
FijiPhil Posted February 24, 2009 Report Share Posted February 24, 2009 Hey, im doing the same thing too! haha I think that the fittings for the ac condensor (i think thats what its called) is different between the automatic and manual cars too, somthing i noticed when looking at mine. Link to comment Share on other sites More sharing options...
vbrad511 Posted February 24, 2009 Report Share Posted February 24, 2009 My 88 WAS an automatic, but all the AC stuff was gone. My 87 donor car supplied all the plumbing, wiring and hardware to get it all running. They had cut the fittings at the firewall, but it the outer lines that they'd cut. I was able to unscrew the fittings and their stubs and replace everything from the manual car. Everything lined right up. Link to comment Share on other sites More sharing options...
Shelby Posted February 24, 2009 Report Share Posted February 24, 2009 the wires for the a/c compressor ad thermo swt only runs in the engine harness for about 2 ft,, the wires come out of the body harness near the ign coil it's an easy matter to just run 2 wires from body connector to the comp and the swt Link to comment Share on other sites More sharing options...
strang3majik Posted February 24, 2009 Author Report Share Posted February 24, 2009 the wires for the a/c compressor ad thermo swt only runs in the engine harness for about 2 ft,, the wires come out of the body harness near the ign coil it's an easy matter to just run 2 wires from body connector to the comp and the swt the harness is cut right in front of the Rad support, and theres about 5 or so wires in there, so, what would they be???...and, by the coil, the plug is still there, just not the relay. Link to comment Share on other sites More sharing options...
vbrad511 Posted February 24, 2009 Report Share Posted February 24, 2009 the harness is cut right in front of the Rad support, and theres about 5 or so wires in there, so, what would they be???...and, by the coil, the plug is still there, just not the relay. Sounds like where mine was cut. Did you say you've got a parts car? You should be able to use the harness pieces from it, all as one chunk of patch/splice. The wires will be color coded. There's a couple of pressure sensors that mount on/near the dryer. That's what those wires are for. Link to comment Share on other sites More sharing options...
bzurc Posted February 26, 2009 Report Share Posted February 26, 2009 To switch to 134a there a few ways to go about it.... The bare bones way is to pick up a couple pounds of 134a, R134a compatible oil, fitting adapters to convert from std. HVAC connectors, and a set of neoprene o-rings. The more complete way would to get the above, along with having replacement HFC-134a compliant hoses made up and replacing the low pressure cutout switch with one that can be adjusted to 134a pressure/temperature relationship. The filter/drier assembly should be replaced anytime the system is open, but some skip this step with mixed results. If you're planning on doing the conversion yourself, you'll need a manifold gauge set w/hoses, a vacuum pump, a syringe to add the oil, and a valve core remover. First, the system should be cleaned as best as possible internally, especially if it has been open to the atmosphere. The compressor should also be removed and drained of any oil that has collected in it, and the proper amount of the 134a compatible oil specified in the service manual (don't have a copy handy) should be added. Compatible o-rings (light green) are used to replace the standard black ones at all connection fittings. Next, The system should be vacuumed as low as possible, preferably to 500 microns or less. Running the pump until the gauge stops moving (should be at least 28"Hg) then an additional 10 min. should be sufficient. The gauge may rise slightly due to moisture evaporating in the system, multiple evacuation cycles may be needed. If the system won't hold a stable vacuum of 28"Hg after a few cycles, a leak is present and must be fixed before continuing. Once the system is holding a vacuum, the charge is then added. To compensate for the variance in capacity, the system will require slightly less refrigerant to remove the proper amount of heat. The easiest way to do this is by using low side pressure to determine proper charge level. Refrigerant should be added to the system from the LOW SIDE ONLY while the air conditioning is engaged and the compressor powered. Start out by adding one pound of refrigerant to the system, then slowly add charge until the low side pressure is between 32psig and 35psig while running under load (preferably a cabin temp of 85 degrees or so). To really do it right, the replacement hoses are needed because HFC-134a molecules are smaller than molecules of CFC-12, and the OEM hoses are actually too porous to contain 134a. If original hoses are used, the system will work fine, but slowely leak refrigerant necessitating frequent top-offs. As said earlier, an adjustable low pressure cut-off switche can be used to allow the system more efficient operation after the conversion, and should be set at 27psig. 134a works more than sufficiently well when the A/C system is properly converted, but if shortcuts are taken the results may be disappointing; A system contaminated with air, moisture, mixed refrigerants will never work as it should. The process is pretty simple as long as one has access to the proper equipment. Also, it goes without saying that if the car's cooling system is borderline, don't bother with the A/C until everything is working as it should. Link to comment Share on other sites More sharing options...
marso Posted February 26, 2009 Report Share Posted February 26, 2009 along with having replacement HFC-134a compliant hoses made up Where can you get hoses made for our cars? Link to comment Share on other sites More sharing options...
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