Stupid AC Dilemma..

[opponheimer]

I put a line I had fabricated for my AC, from firewall to compressor. Then I go to charge it, and uhh.. no Low Pressure port.. Crap! Was it supposed to be on the line that was fabricated? Is there any way else I could charge the system? Or could a shop charge it through the High Pressure Line?

Thanks

[Z U L8R]

if firestone can't charge on the high pressure side then no one can, you need a low pressure port >_< doh!

[opponheimer]

I got a LP fitting attached and tried charging the system, the compressor wouldnt cut on, the AC button was depressed also.. I have the correct wire making contact with the compressor plug... I may test it for voltage... An s14 w/ s13 sr20det shoudl not have an AC wired from the ecu correct?

[FRpilot]

check out the a/c sticky thread on freshalloy under 'best of 240'
more details on getting the a/c button to light up and probably your a/c compressor to turn on.

also, im not sure about wiring. when you turn on the a/c, extra load is put onto the engine and will drop the rpms so it might stall. the car is suppose to raise the rpm idle when you turn on the a/c so stalling doesnt happen. i read that this function in the sr a/c is controlled by the sr ecu while the ka is controlled by something else (im not sure, probably fuse box or something). i didnt get too much more into it since im running pfc on my sr.

[nrg]

yes, the low pressure valve supposed to be on the line you fabed up. you probably accidentally cut it off lol.

the high pressure valve isn't a vacuum, it's a discharge valve. that line is used for a machine to create a vacuum in the AC lines.

[opponheimer]

I got an LP line, charged the system, hardwired the compressor to cut on temporarily and the damn thing wont blow any cold air.. The triple pressure switch is broken btw. What exactly does the triple pressure switch do?

[koukimonster139]

turns the compressor on when there is enough freon in the system.

in other words, your compressor wont work if this part is faulty.

dont hardwire your compressor at this time, it probably has no oil in it

[Z U L8R]

lol nrg you're close. when you vacuum down a system you vac down the high and low side, however when you add freon you can only add through the low side.

you're correct, the ecu doesn't control the s13's ac, but your dash plug needs to be wired right. basically make sure the triple pressure switch wire, the ac fan wire, and the ac relay wires are all jumped together on the dash plug of the s13 sr's converted engine harness. then you need to bump some freon in it because the triple pressure switch will keep the compressor from coming on if there's no freon in it, once you get the compressor to start cycling, you want your low side about 30-35, and your high side bout 175-185 since it's hot as hell outside...

[Z U L8R]

the triple pressure switch, cuts off the compressor if pressure is too high or too low, if you hardwire it and the head temps in go up too high you'll pop the friggin hose off the compressor.

not enough freon = not cold
too much freon = not cold
bad expansion valve (replaced a couple on 240's) = not cold
moisture in the system aka need to replace the receiver dryer = not cold

[opponheimer]

I had the system professionally vaccumed at 29 inch /lb vaccum for 30min, and yeah... the low pressure side is at about 100psi... The idiot at the ac shop said I'd need 23fl oz of 134 and so i kept filling her up.. then i noticed a tag on the car that called for 8.5 fl oz.. I guess I'd better bleed it..

When I hardwired the ac compressor and the clutch kicked in, it was making a loud knocking noise.. I'm guessing thats not desireable either. Could it be from too much pressure? I know the compressor is a positive displacement pump.. I could be overworking it..

So a triple pressure switch from a 96 auto 240 is different from all other nissan/infiniti's I've seen at the junk yards. Should i try and find only what came with the vehicle or could I just change the switch and rewire it (though there are 4 wires and the other switches I've seen had 2 wire plugs.

[Z U L8R]

as far as the tr pr sw, if your s14's engine main harness has a 4 wire, then go with a 4 wire, and 100psi on low side is WAAAAAAAAAAY FUCKING TOO MUCH hahaha

good luck bro