Aircon wiring fault?

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Dhendo
Posts: 3
Joined: Sat Dec 20, 2008 3:14 am
Location: Victoria, Australia

Aircon wiring fault?

Post by Dhendo »

Hi all, new to this forum. I recently bought a 1998 Nubira wagon, the drive home revealed a couple of problems, the heater fan and aircon didn't go. The fan was easily fixed, once I found my way into the dashboard, just a connector unplugged at the controls, but the AC is a mystery,everything appears in order but the relay for the compressor clutch doesn't operate with the switch. There is power to pin 85 of the relay as soon as the ignition switch is on, but pin 86 has no connection to complete the circuit, if pin 86 is earthed the relay pulls in and the compressor runs. Testing the wiring behind the fuse/relay panel shows no wires connected to pin 86.
Are there any wiring experts there, or anyone solved a similar problem?
Thanks for any help, Don.
Daniel
Expert
Posts: 1298
Joined: Mon May 03, 2004 8:28 am
Location: Belgium

Post by Daniel »

You may be low in refrigerant pressure due to a leak. Or have a defective (rare) pressure sensor. The ECU can't send ground to pin 86 in that case.

Daniel
Dhendo
Posts: 3
Joined: Sat Dec 20, 2008 3:14 am
Location: Victoria, Australia

Post by Dhendo »

Thanks Daniel, that explains the mystery, but also raises another question, will a fault be recorded by the ECU in this case, and will it be indicated somehow, I'm new to this car and not aware of how faults are indicated.
Don.
kojack
Posts: 2
Joined: Sat Jan 03, 2009 10:01 pm

Re: Aircon wiring fault?

Post by kojack »

Dhendo wrote:Hi all, new to this forum. I recently bought a 1998 Nubira wagon, the drive home revealed a couple of problems, the heater fan and aircon didn't go. The fan was easily fixed, once I found my way into the dashboard, just a connector unplugged at the controls, but the AC is a mystery,everything appears in order but the relay for the compressor clutch doesn't operate with the switch. There is power to pin 85 of the relay as soon as the ignition switch is on, but pin 86 has no connection to complete the circuit, if pin 86 is earthed the relay pulls in and the compressor runs. Testing the wiring behind the fuse/relay panel shows no wires connected to pin 86.
Are there any wiring experts there, or anyone solved a similar problem?
Thanks for any help, Don.
The Air-con could be similar to my current problems - this also sounds like the answer: http://wiki.answers.com/Q/Discuss:How_d ... w_cold_air

I am currently at the stage of trying to work out how to get the Air-con controls out of the dash to check the soldering in the back. Can anyone help me with that? I have struggled to find where the appropriate screws are...
kojack
Posts: 2
Joined: Sat Jan 03, 2009 10:01 pm

Post by kojack »

I seem to have my Air-con issues sorted out... ended up being a 3 step process...

1. get the cover off the central dash - actually is easier than I expected as it has about 6 'latches' around the silver plastic facia. Carefully use a flathead screwdriver to lever these off and it comes off very nicely. Once that is off, there are screws to remove the Air-con unit (and also the stereo unit etc. for very simple removal!)

2. Pull the Air-con control unit out and pull it apart. Take not of the spring inside for the central vent switch, and also be careful with the 'hot-cold' selector as you will need to put this back together carefully. Simply adding a bit of solder onto each of the 7 connectors between the 2 motherboards inside did the trick to get the switches working reliably.

3. Put it all back together - but this had another issue for me, as I'm not sure if it was faulty beforehand or I didn't take care with it, but the cable connecting the "hot-cold" selector had come out of it's connector... had to tape it up carefully to get it working again... PLUS find the other end of this cable (it's just under the driver's side) and ensure it is working well... otherwise you'll find it's stuck in a single position - in my case it was in "hot" therefore when I was trying to test out the Air-con working it appeared to not be having much effect since it was combining with the heater!

Hope this helps someone... ;)
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