**S14 w/Redtop SR20 and AC Problem!!!**

[midnight_rex]

So i finally decided to hook up all my AC stuff i had just sitting in my patio (which was covered up) in my s14 with a redtop SR20. Im having a problem with the AC clutch to engage when i press the AC button inside the car. so here goes the story...

***im using ALL S14 AC LINES. NO CUSTOM LINES. im also using the S14 KA compressor**

I have everything hooked up and prefectly aligned. the only way that i get the AC clutch to engage is to jump 2 wires from the triple pressure switch on the drier. the clutch would not engage by just pressing the AC button inside the car. Today me a friend of mine jump the 2 wires and hook up a can of freon while the clutch is engaged. freon goes in fine and the air blowing inside the car is cold!!! I figured if i got some sort of pressure in the lines that the AC clutch would finally engage from the signal that the triple pressure switch gives out. I plugged the triple pressure switch back up and still the clutch will not engage. its like the triple pressure switch is keeping the curcuit open and not letting any voltage to the AC clutch.

i even went off a source from Freshalloy's forum which says in quote

STEP 2 WIRING

This was the simplest part , on the s14 the plug for the compressor is not on the engine harness as for the SR, the s14 has the plug on the driverside fender well , this comes from the main harness that goes by the driverside fender. Well since your using your original compressor you will find that it plugs right in just as it did before. However when you push the a/c button on the dashboard nothing happens. you will notice that all of the other controls work except for the a/c button. you might also notcie if you jump the relay in the fuse box that the clutch will engage and compressor will turno on, but we want it to work like stock with the button on the dasboard. So here is what you do

***** this is the big secret that the wiring people wont tell you ****

on the f3 conector (big white plug under dashboard near passenger foot well , you know the one you have to splice into to make your engine swap work) you need to splice together the following cables pin 16 yellow/ black to pin 43 or 46 (cant remeber now im at work) black/pink. and what do you know voila it works, push the a/c button a/c turns on, pust it again it turns off. 2 friggin wires, it was staring me in the face for like a week before i tried it , it seemed to easy, thats it just sauder those two wires togerther and ti will work like stock.

the only issure is wiring it into the idle air control valve so the rpms wont drop as much but i dont really think that is an issure as i have not had any problems with it yet its not to bad but i already pretty much got that figured out and iwill be doing it at some point later this week i will post it then. hope this helps some of you people sweating in your car, cuz ill tell you here in miami i is hot as biatch

i did this and it didnt work. i figured that those wires come from the interior wiring to the white plug which goes back to the engine. my wiring was done by 786 motoring here in houston, tx and i found that the yellow/black and black/pink wires were cut intirely from the white plug going back to the engine. i dont see why the AC switch wire and the triple pressure switch signal wire needs to be looped together??? could this be a bypass?? and why do these wires go back to the engine harness?

also could it be a possibility that my pressure switch is no good? how can i check to see if the pressure switch is any good? i just wanna get the AC compressor to operate when i press the AC button inside the car and also operate off the pressure switch.

does anyone here on this forum have a s14 with a redtop sr20 running AC or have the same setup as me??????? i really wanna get this working since i busted my butt getting all the lines in. any info would be appreciated. thanks :)

[boostin13b]

I'd have to dig up the wiring. I've got a Red top in an S14 same setup. All KA running equipment bolted to SR. Your pressure switch needs to have the correct amount of freon in order to complete the circuit. If it has some but not enough it won't engage the clutch. I would not recommend just hard wiring it through your switch like you want. You also have to include the fan to kick in otherwise your pressures will skyrocket and your switch will keep cutting off the compressor not to mention it won't cool well. In order to check to see if you have the correct amount of freon in it you need a gauge set.

Did you release any freon when you did the swap? If so did you pull a vacume before you charged it? How much did you install? etc.

You may have problems with the car not idling well with A/C if they didn't wire in the IAC idle up signal to the ECU.

[midnight_rex]

i did vacuum my lines before i added freon for 30 minutes. i only added one can of freon and the AC was blowing cold. we had a set of gauge and it was reading between 30 and 40 psi which should be average. that was just with one can of freon. All the AC stuff was already out of the car when i bought it but the buyer did give me the AC lines with the sale of the car.

the idle was fine when the AC compressor was engaged.

[boostin13b]

It should be around 30-35 on the low side and 190-230 on the high with the fan blowing and revving around 1700 rpm. It sounds like you may have enough freon but If I remember right the A/C switch needs more than one input in order to send the signal to the pressure switch just for safety measures. I'll have to dig up a diagram.

[midnight_rex]

dude if you can give me a diagram then i would really appreciate it!! how do u have your setup wired up?

[midnight_rex]

anyone else had this same problem as me?

[Om1kron]

I don't understand what the problem is, so you connected the yellow/black, and black/purple wires together on the f3 plug like instructed?

Or do you think you have to run them somewhere? All you do is connect them, like penis and vagina man, like two fingers together when telling a lie. Tape it up or solder and put the cap back on the plug.

so when you push the ac button the clutch doesn't engage still?

have you tried reading the FSM at all to diagnose your situation?

You are aware that big book of instructions has your answers in it right?

[midnight_rex]

yes i connected the yellow/black and black/pink wire together on the harness terminal side but not on the plug side. wouldn't it be the same thing if i connected them the other way also?

when i push the button the AC clutch still doesn't engage.

i just got a FSM resource today to diagnose the AC electric system.

what sux is i found out i have a leak in one of the lines on the condenser. ill have to get another condenser and try out another working triple pressure switch.

[Om1kron]

yes i connected the yellow/black and black/pink wire together on the harness terminal side but not on the plug side.

Sounds like you already fucked up.

http://img.photobucket.com/albums/v46/om1kron/My%20Cars/1996%20240sx%20Kouki/2008-11-29%20-%20Harness/2008-12-01025_zps3079113c.jpg

f3 plug in the picture above... that's where you jump the wires. Technically it's the same if you do it on the M64 plug I think it's called (the female plug this goes into) But it's obviously easier to do it on the f3.

When i push the button the AC clutch still doesn't engage.
Have you checked the A/C fuse on the driver side of the car, I can't remember but I'm sure there is one there too.

i just got a FSM resource today to diagnose the AC electric system.
This will be your best bet.

what sux is i found out i have a leak in one of the lines on the condenser. ill have to get another condenser and try out another working triple pressure switch.

Would be rare if it was the condenser's clutch that went bad. A Multi Meter would be your best friend at this point and going step by step with the manual so you're not replacing shit that doesn't need to be replaced.

I almost replaced a fuel pump once because it wasn't priming, turns out I had a kill switch in my car the dealer installed I didn't know about. And it was triggered by something that flipped it in my glovebox lol. (older car)

[chituntang]

The two wires are together now because SR and KA does different things to active AC in the S chassis. SR, if I remember correctly, actually monitors the AC system when the KA does not. After the engine swap, the SR ecu will not let the AC turn on, even all the stuff is hook, unless you use all SR wiring (a little hard for S13 SR to S14 240sx).

The way I check if it works is I put the key in, put in at on position, have a friend at the engine bay, and hit the AC switch. If it works, your buddy will hear a click, if not, its not working.

[midnight_rex]

Sounds like you already fucked up.

http://img.photobucket.com/albums/v46/om1kron/My%20Cars/1996%20240sx%20Kouki/2008-11-29%20-%20Harness/2008-12-01025.jpg

f3 plug in the picture above... that's where you jump the wires. Technically it's the same if you do it on the M64 plug I think it's called (the female plug this goes into) But it's obviously easier to do it on the f3.


Have you checked the A/C fuse on the driver side of the car, I can't remember but I'm sure there is one there too.


This will be your best bet.



Would be rare if it was the condenser's clutch that went bad. A Multi Meter would be your best friend at this point and going step by step with the manual so you're not replacing shit that doesn't need to be replaced.

I almost replaced a fuel pump once because it wasn't priming, turns out I had a kill switch in my car the dealer installed I didn't know about. And it was triggered by something that flipped it in my glovebox lol. (older car)

on my F3 plug the yellow/blk and blk/pink wires are cut right at the plug. i took off the electrical tape that was wraped around the wires and discovered that those 2 wires looked to be completely taken out. it would be very difficult to extend those 2 wires and jump them from the F3 plug.

yes i did check the AC fuse in the fuse box on the driver side footwell. i checked all fuses and i replaced the relay in the engine bay with a new one.

i will need to get a condenser anyways cause its leaking. i found a guy here in houston who is parting out a completely stock s14 with good working AC. im going to get the condenser and the pressure switch from him.

The two wires are together now because SR and KA does different things to active AC in the S chassis. SR, if I remember correctly, actually monitors the AC system when the KA does not. After the engine swap, the SR ecu will not let the AC turn on, even all the stuff is hook, unless you use all SR wiring (a little hard for S13 SR to S14 240sx).

The way I check if it works is I put the key in, put in at on position, have a friend at the engine bay, and hit the AC switch. If it works, your buddy will hear a click, if not, its not working.
i dont really understand how that would affect the AC wiring when all is modified when a s13 sr is put into a s14 is the engine harness? i do understand what your saying about checking for the clutch engaging

thanks for the replies. im getting more help from here than the nicco forums.

[Om1kron]

haha nico... that place still exists.

Anyway yeah the only reason why I said it would be best to jump those pins on the f3 plug rather than the body harness plug is that it's reversable. Once you start jumping shit on the body harness it's hard to pinpoint or troubleshoot stuff that requires you to unbolts a lot of stuff like the blower motor to get to the back of that m64 plug.

But from what you're saying the person that did your wiring completely de-pinned those two plugs.

If anything you can check to see if any other wires may be left over on that f3 plug like the gst port, or the other metering devices that you may never ever ever hook your car up to has the plugs in tact, it's a bit tricky to de-pin something on that f3 plug. But i'd re-use some wires going to something I wont utilize rather than having them there for no reason.

Good luck either way with the new condensor.

[boostin13b]

It's best to use the F3 plug, if the wiring was done correctly, it shouldn't be bad at all. On S14's, the ECU sends most of the ground signals to your relays to turn them on. with the ECU gone you will have to make your own circuits and work them into the S13 harness.

[midnight_rex]

im gonna get this condenser in and loop the wires from the 3 plug. i hope it works.

om1kron, im gonna see what other wires arent being used on the f3 plug. i wish i knew how to take the pins out of the f3 plug. there is very little wire to work with on the 2 wires i need to splice together :(

again, thanks for the help

[midnight_rex]

well tonight i followed the diagnosing procedures from the FSM. everything checked out good. some tests werent possible due to my car using a 62 ecu for my redtop SR. my relay connections, compressor connections, and triple pressure switch connections all came out to have continuity and correct voltage.

i connected the 2 wires at the f3 plug like boostin13b and om1kron suggested before diagnosing.

im still going to change out that triple pressure switch with a known working one. i dont see why i was having a problem in the first place. i cant wait to have AC this summer.

one thing i did check when i was connecting the 2 wires together at the f3 plug was voltage from the AC switch wire and voltage from the triple pressure signal wire. since they are connected together now i decided to put the multimeter up to it. when i have the AC button OFF there is 12v going thru both wires. when i turn the AC button to ON there is little voltage going thru. why is this?????????

[boostin13b]

well tonight i followed the diagnosing procedures from the FSM. everything checked out good. some tests werent possible due to my car using a 62 ecu for my redtop SR. my relay connections, compressor connections, and triple pressure switch connections all came out to have continuity and correct voltage.

i connected the 2 wires at the f3 plug like boostin13b and om1kron suggested before diagnosing.

im still going to change out that triple pressure switch with a known working one. i dont see why i was having a problem in the first place. i cant wait to have AC this summer.

one thing i did check when i was connecting the 2 wires together at the f3 plug was voltage from the AC switch wire and voltage from the triple pressure signal wire. since they are connected together now i decided to put the multimeter up to it. when i have the AC button OFF there is 12v going thru both wires. when i turn the AC button to ON there is little voltage going thru. why is this?????????

Because you are completing the circuit. When you add the ground and energize whatever you are using it uses the voltage. You should have less than .5 Volt when energized. anything more and you have too much resistance somewhere in that circuit after where you measured it. It really should be less than .1 volt but depending on connector conditions and such you can build up some resistance fast.

This is a good sign if the relay is closing. It depending on which wires you tested might mean your pressure switch is good. They rarely go bad. remember if you plan on using a known good switch you have to lose all your freon that is currently in the car. This means Evac and charge again and depending on your situation it could get expensive. don't pull off the switch without pulling the freon out of the system or you might freeze your eyebrows.

[midnight_rex]

well i got my AC to work. all because i didnt splice the 2 wires at the F3 plug. AC blows so cold! i love it!