Jump to content
SAU Community

Recommended Posts

hey guys, ive had air con trouble since i bought my gtst. No cold air

Ive since fixed leaks and replaced faulty sensors. Now diagnostics check is good, BUT, my compressor does not kick in unless i overide the computer by touching a wire from the negative terminal of the battery to the pressure switch at the front of the car where the gas cylinder is. Then the compressor kicks in and i get cold air.

mechanics have told me it could be the thermostat, and that i should try overiding that to see if its faulty. what i dont know is exactly where the thermostat is to put a wire in to overide it?

can someone post a photo or describe where this unit is, and where the connection is to overide?

Edited by Archie

The switch on the top of the dryer ( the gas cylinder thing ) is a pressure switch, it stops the compressor kicking in if you don't have enough pressure in the system. 'If' you have the correct amount of gas in the system, and bridging out the pressure switch gets it all working, wouldn't it appear that is a problem with the pressure switch?

Edited by heller44

check wether pin 9 on the eccs is going low 0v when trying to cool on air con. if not, then check pin 46 on eccs if that is going low 0v. pin 9 is out to pressure switch to pull aircon relay in, pin 46 is in from auto amplifier (climate control). If you don't get it there check pin 15 on climate control thats the origination point.

If your diagnostics on all sensors are good, this is about your next step.

yeah, i had the car at the mechanic today, and he told me that there was a problem of something not earthing somewhere. i think thats why the compressor kicks in when he bridged to the pressure switch from the negative terminal of the battery.

With reference to the diagram, all you are testing doing that is that the aircon relay works and the compressor clutch works, not all the rest of the crap which controls it.. the ecu is what turns on the air con relay, it is just told to do it by the climate control module.

You say you've had sensors replaced.

I have recently had the exact same issue and it turned out my Intake air temp sensor is constantly reading -30degree's (occasionally comes up to 8degree's or so).

This stops the a/c compressor cutting in.

Have you entered the climate control diag mode and had a look at the intake temp sensor reading?

Mine doesn't always show up the Intake temp sensor in the sensor check.

The only way to be sure is for myself to flick to the sensor display and check them.. Often than not when its -20 it doesn't show as faulty but it sure isn't -20degree's so its faulty and causes the a/c not to operate.

Did you replace the Intake temp sensor? I can't appear to find the sucker.

yeah im pretty sure i did replace that sensor. i had to remove the entire dash (which took a long time, but i was being careful not to damage anything, cos you so easily can) and then where the aircon box is behind the glove box, the sensor is one of the 3 connectors that sit on top of the aircon box.

Its the left, white connector. The middle one is black (thats the refrigerant temp sonsor connector), and the right one is white (that connects back to the climate control unit).

The actual intake air sensor is inside the aircon box (if you follow the wires you'll see). i had to pull the stuffed senor out (forcefully) by yanking the wire and dislodging the sensor. then i inserted my new second hand sensor (which i pulled from an old aircon box to get the spare intake sensor). i pretty much just had to let the sensor hang inside, cos otherwise i would of had to degas the whole system and then remove the aircon box and open it up. But i had just had it regased so i wasnt gonna do that.

Now ive just found out that my water temp sensor is showing up on the diagnostics check (No. 23 flashes)

Would this sensor be enough to stop the compressor from kicking in? And also, is this sensor under the car?

thanks cubes.

Hey, where abouts in SA are you? Ive been going to Synergy Motorsport at Medindie Gardens on main north road to try and get this aircon bullshit sorted. Im not sure if they still are PVP imports anymore aswell as Synergy?

Cars been good.

Owned it for 5yrs, clocked up ~160,000km's of my own and now its starting to show its age.

The clock states its done 230,000km's.

Just bought myself a press and bushes for the front and rear I will be doing them once I get this aircon sensor and track down heater core for a reasonable price.

The highpressure aircon hose recently went after a conversion to 134a (134a runs double the pressure of the old R12 gas).

The top radiator tank let go in the early days, Natrad in the city replaced that for $90.

Clutch master and slave cylinder went, they were $75 and $30 each bran new. All Clutch and Brake at St. mary's does them so look in the SA sections workshop sticky.

Nothing else really.. Its been a great reliable car.

Only replaced motor as I got tired of the rb20 and had been building up the 3ltr for a couple of years prior so ripped it out sold it and dropped the 3ltr in.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • LOL.... a good amount of people (not all) on that continent seem to know everything and like to measure things in bananas, football fields, statue of liberties instead of the metric system lol.
    • I assume the modules are similar enough, so if you've had no issues I don't see why I would. I have tried to find a wiring diagram for the FPCM / fuel pump circuit, but I can't find it anywhere. Otherwise, I would just do some wire cutting and joining at the FPCM and give the 12 V supplied to the FPCM directly to the pump instead. If you know anyone that could help with wiring diagrams, I'd be very happy  
    • If it dies, then bypass. The task isn't difficult. I have one running on a standard R32 FPCM. That's after nearly 20 years of it running an 040, which pull substantially more current than the Walbro. They're not the same module, but I'd hope it indicates that the R33 one should be man enough for the job. I think people kill them when putting proper sized pumps on them, not these little toy pumps we're talking about here.
    • Silicone spray won't hurt anything. And if it does, that's an opportunity to put some solid steel spherical bushings in, so you can really learn what suspension noise sounds like, If you're going to try it, just spray one bush at a time, so you can work out which one is actually noisy. My best guess is that if the noise started only since putting the coilovers in, then it is just noise being transmitted up through the top mounts of the struts, and not necessarily "new" noise from bushes. But it's almost impossible to know.
    • Are you saying the 34 is SUV height, and not that we're talking about an SUV here? (because if we're talking about an SUV, you don't fix them. You just replace them when something breaks. Not worth establishing sufficient emotional connection with an SUV to warrant doing any work on one). I wouldn't jack my car up on a short little loop of 10mm steel rod poking out through a hole in the bumper bar, front or rear end. I realise that we're probably not talking about that type of loop at the front, being the one under/behind the bar on a Skyline.... but even for that one, trying to jack up on what amounts to a thin piece of steel, designed purely for withstanding a horizontal tension force, not a vertical compressive force (and so would be prone to buckling/crushing) and, my most particular bitch about it - located RIGHT AT THE EXTREME FRONT OF THE CAR, applying a load up through the radiator support panel, etc, with almost the entire mass of the car cantilevered between there and the rear wheels? Nope. Not doing that. Not on the regular. That structure out there in front of the front crossmember is not designed to carry load in the vertical direction. Not really designed to carry any load at all, really. The chassis rail that the tow point is connected to would be fine loaded in tension, as per towing. Not intended to carry the mass of the whole car, especially loaded all on one rail, with twisting and all sorts of shitty load distribution going on. No, I will happily drive up on some pieces of wood, thanks. That can only happen on driven wheels, and they are at the other end of the car, and this problem does not exist at that end of the car. And even then, I have been known to drive up on at least 1x piece of 2x8 each side at the rear, simply to reduce the amount of jack pumping necessary to get the car up high enough for the jack stands. What really really shits me about Skylines is the lack of decent places for chassis stands at either end of the car. You'd think they'd be designed into the crossmembers.
×
×
  • Create New...