Aircon Help Needed :)

[lwells]

Hi All,

Hoping a few aircon gurus are floating around.

I finally got around to have my aircon converted to 134a. The system (ie compressor, etc) is fine -- no leaks or loss of compression -- but the system won't come on unless you muck around with the relays.

The aircon guy had a fiddle but couldn't get it to "go" (without playing with the relays). Basically something between the control panel and the relays doesn't seem to be working.

When I got home I went through the diagnostic mode and got a "25" and "-26" error. According to the workshop manual that means there is an error with the sunlight sensor (25) and a shorted PBR sensor (26).

I'm guessing the problem with the sunlight sensor was that it was being blocked, so I am not overly concered about that. The PBR sensor is more of a worry because the system is reporting that its shorted. First off, can someone explain WTF the PBR sensor is and what it does? Secondly, whats the go with fixing a shorted sensor? Finally, is a shorted PBR likely to be why the aircon won't come on unless manually started via the relays?

Cheers,

Lucien.

[SteveL]

I'm guessing the problem with the sunlight sensor was that it was being blocked, so I am not overly concered about that.  The PBR sensor is more of a worry because the system is reporting that its shorted.  First off, can someone explain WTF the PBR sensor is and what it does?  Secondly, whats the go with fixing a shorted sensor?  Finally, is a shorted PBR likely to be why the aircon won't come on unless manually started via the relays?

Check page HA13 of the factory WS manual, it describes how to check the PBR sensor. Seems to measure the air mix on the outlet to the cabin.

[lwells]

Good news! It was just a busted fuse. Hopefully the fuse didn't blow recently

I have cold air. Weeeeee!

LW.

[predator]

You suck..

mine has blown fuses.. removed belt and probably seized compressor (hence why they removed the belt I would say)..

I'm so glad I got that aircon exemption :idea:

[lwells]

Check page HA13 of the factory WS manual, it describes how to check the PBR sensor.  Seems to measure the air mix on the outlet to the cabin.

Hi Steve,

Yeah, but the description sucks I found some helpful stuff on the Hong Kong Skyline club: apparently PBR stands for Potention Balance Resistor, and is part of the cooling coil in the mode door motor, which is attached to the heater.

http://www.hkskylineclub.com/new/forum_pos...sp?TID=310&PN=1

Now I just have to work out what the other two missing fuses are for: #2 (ignition "Electronic Parts") and #3 ("Transmission Control" -- given its a manual this obviously isn't an issue).

Anyone have a clue what the #2 fuse actually does (on a R32 GT-R)? Can't find any info and I haven't noticed any obvious things not working in the car.

predator: Arr, that sucks. Those aircon assemblies can be quite expensive to buy

LW.

[lwells]

Bump.

Anyone got a clue what the #2 fuse is for?

Lucien.

[The Dan]

Hehe, turn everything on and pull the fuse. Whatever stops working. lol.

I have never really worried about what the fuses were for. If it is blown, replace it.

[lwells]

Annoyingly, the fuse I replaced popped again after about an hour of driving with the aircon on. *sigh*.

Any clever suggestions on finding whatever is drawing that little bit too much?

Edit: Whoops. I meant the aircon was on for about an hour before the fuse died.

Cheers,

Lucien.