View topic - Air Con problems

Air Con problems

Get your electrical juices flowing - ask those auto electrical questions here
User avatar
Been here a while
 
Posts: 208
Joined: September 3rd, 2009, 9:57 pm
Location: Port Hedland, WA

Air Con problems

Having Air Con problems?

When I start my Disco, I have to turn the Air con off and turn it back on for it to work.
Even when the engine is running, sometimes it switches off and on, several times quickly. If I turn it up or turn it off, sometimes it sorts the problem.

I noticed it first happening when we took a trip to Darwin and had to do several deep water crossings. I'm guessing that water got into the system somewhere. For the rest of the trip the air con would switch on and off at times but only at low power speeds.

I was hoping the problem would get better and that it was a damp problem and would dry out. For a short time it was getting better but of late, seems to getting worse.

I am assuming that its electrical rather than anything else.

Hoping someone has a easy solution.

Unread postby Hocks » August 24th, 2011, 12:08 am


Moderator
 
Posts: 911
Joined: October 2nd, 2009, 1:27 pm

Re: Air Con problems

you could be lucky and there could be a loose connector to one of the pressure switch or similar.

or
one of the connectors to the pressure switch or speed sensor or clutch on the compressor is oxidised (rusted...). Might be fixable just by removing connectors and reconnecting them.

or
Probably a faulty TX valve or refridgerant pressure switch.

Unread postby SimHilux » August 24th, 2011, 11:23 pm


User avatar
Been here a while
 
Posts: 208
Joined: September 3rd, 2009, 9:57 pm
Location: Port Hedland, WA

Re: Air Con problems

When it switches on and off, it sounds like the air con bit behind the dash is cutting out.

Will have a look over the next few days. Hopefully, if it doesn't mean, taking to long. Not got any more rest days until next weekend and off to Broome for that weekend.

Serviced her today, wasn't in the right frame of mine and was making some very stupid mistakes, didn't help, that I was being interrupted every five minutes. Even forgot to put the sump plug in but didn't loose too much before I remembered.

What a day.

Unread postby Hocks » August 25th, 2011, 12:42 am


User avatar
Part of the furniture
 
Posts: 1155
Joined: February 6th, 2008, 9:16 am

Re: Air Con problems

Hocks wrote: Even forgot to put the sump plug in but didn't loose too much before I remembered.


Kitty litter!!!

Unread postby V Williamson » August 25th, 2011, 3:38 pm


User avatar
Been here a while
 
Posts: 208
Joined: September 3rd, 2009, 9:57 pm
Location: Port Hedland, WA

Re: Air Con problems

Had a quick look at the connections and everything looks good but it did run OK for a while and since we have had bad weather, its got worse again. Fingers crossed its just a bad connection or simular.

My next ponder is, being a series one Disco, the air con is not the most powerful and only gets blown out through the dash, nothing towards the feet.
I am sure it aint going to be cheap but I am very happy with my 4wd, done lots on it and I know how it runs, doesn't have any major issues so rather than buying a newer one, what options do I have in regards to improving the Air con?

Most of the year its fine but living in the sunny Pilbara where we have had tempetures reaching the mid 50's, the car struggles to cool it down and then I get nagged by the handbrake.......Hope she's not listening....Roothys fault.

Unread postby Hocks » January 16th, 2012, 12:45 am


User avatar
Part of the furniture
 
Posts: 1326
Joined: May 3rd, 2009, 8:36 pm
Location: Dapto, NSW

Re: Air Con problems

Have you checked your condensor for a built up of crap? It may be shutting down because the pressure is getting too high. An air flow blockage will prevent heat transfer, thus causing higher pressures. That is possible why it works ok for a while the plays up.
2000 Prado 3.0LTD Lifted and Locked
http://www.4wdaction.com.au/forum/viewt ... 22&t=87167
Have IFS, Will Impress

Unread postby worthy » January 16th, 2012, 9:28 am


Need to get out more
 
Posts: 4722
Joined: August 4th, 2011, 10:43 pm

Re: Air Con problems

If the aircon is switching on and off on by itself then it seems you have a loose connector/broken wire somewhere under the dash. Look for the area around where feet kick things and also the fan variable speed resistor in the cool air flow duct just after the evaporator/the cold bit.

Hope you find it.

mydmax

Unread postby mydmax » January 16th, 2012, 12:36 pm


User avatar
Been here a while
 
Posts: 255
Joined: May 7th, 2010, 7:05 pm
Location: Mackay, QLD

Re: Air Con problems

It could also possibly be a blocked up evaporator under the dash. Once the ac has been one for a few minutes and the evaporator gets a sweat up it's tricking the thermostat into thinking it is colder than it really is thus causing the system to cycle on and off too often

Unread postby danielk » January 16th, 2012, 12:55 pm


User avatar
Been here a while
 
Posts: 208
Joined: September 3rd, 2009, 9:57 pm
Location: Port Hedland, WA

Re: Air Con problems

It normally doesn't work when the engine is started and takes some playing with.

It very rarly cuts out once it is running. Only if you start playing with it again.
It might even be the control unit. Because if it does cut out, it only stops blowing cold air, it starts to blow warm air.
Thinking that it might be to do with the reciculation switch.

In newer cars, you have to switch it on to recycle, on mine as it is a series one Disco, it only has a sliding thing, which has air con, air con mixed with normal, normal heater and something else. I would love to update the system but feel it will cost too much, require the whole dash to be pulled out and half of it replaced. I'm going to take it to a local air con place and see what they have to say.

The guy I brought it of upgraded it to the newer stuff, R134 I think, or R12, the newer one.
In perth its good but up her where tempetures reach the 50's, I need a bit more. Plus it only blows out through the dash and not on the feet.

Any advise will be great.

Unread postby Hocks » January 17th, 2012, 10:10 pm


I'm new, be nice!
 
Posts: 3
Joined: January 15th, 2012, 2:14 pm

Re: Air Con problems

You may also be short of refrigerant in the system. Often after converting from R12 to R134a the compressor seals would start to leak because they weren't designed to cope with the new refrigerant and oil used.

There should be a pressure switch in the system usually monitoring high and low refrigerant pressure. It stops the compressor running if the gas pressure gets too high, such as a blocked condensor, or gets too low, such as a gas leak. The compressor can often cycle on this switch, turning back on as soon the pressures return to normal once the compressor stops running.

If you have a look at the sight glass on top of the black refrigerant filter dryer near the condensor, you can get an indication of the level of refrigerant charge. When the compressor is running and engine revs about 1500, and with the cabin temperature set to low with the fan on high, check the sight glass with a torch to look for bubbles in the liquid under the glass. With a full gas charge this glass should be clear(liquid only), when the compressor cuts out, bubbles should appear in the glass as the refrigerant boils off. This is important because no gas at all makes the sight glass clear as well. However with no gas at all, the compressor should not run.

Another simple test while the compressor is running and engine revs about 1500, the cabin fan is on high and set to maximum cooling, is to feel the suction pipe coming back into the compressor. It is the larger of the two pipes and the best place to feel the temperature is on one of the aluminium fittings, not the hose. It should be sweating and feel very cold, maybe 10 to 15 deg C. If it is not cold, this may indicate a shortage of gas as well.

WARNING: The smaller of the two pipes is the hot gas discharge pipe and is extremely hot, don't grab it by accident.

Good luck.

Unread postby gkamholtz » January 18th, 2012, 8:13 am


User avatar
Been here a while
 
Posts: 208
Joined: September 3rd, 2009, 9:57 pm
Location: Port Hedland, WA

Re: Air Con problems

Problem sorted, cost $500 to repair, was only a hoses leaking and what an expensive hoses.

But it is all good now.

Thanks everyone for the advise.

Unread postby Hocks » March 1st, 2012, 2:13 pm



Return to Electrical

Who is online

Users browsing this forum: anybot, Bing [Bot]

Advertisement