Help with Air condition switch

rjb · 09-05-2005, 11:01 AM

I replaced my center console and had to remove all the switches inclusive of the air conditioer switch. At the top of the switch there is a metal tube that broke off when I removed it.

What does this tube do and do I need it ?
Can it be bypassed?

I have the original air condition unit still and since the tube has been broken off, it doesn't get cold inside.

Please advise what to do.

TCB · 09-05-2005, 11:14 AM

The tube has to to with temp control. I believe the green wire passes through this switch to the fan switch. You can bypass the temp control switch and it should work, you just have to adjust your own temp..

Hugh R · 09-05-2005, 11:24 AM

The tube goes into the evaporator in the smugglers box. Don't know if you can get a new one from Pelican or not. But TCB is right that you should be able to connect the wires together behind the temp control knob and get cold air, unregulated, meaning it will just run. You can stick a dial type thermometer in your dash vent and turn the fan off and on it it gets down to 32 degrees, (unlikely), but you never know. Below freezing, the evaporator will ice up.

rjb · 09-05-2005, 04:53 PM

Can you post what wires to connect together to bypass this.

rjb · 09-05-2005, 05:21 PM

Do you guys mean connect both green wires together???

DonMo · DonMo's Garage

Yes, the switch just senses the temp in the tube and is on or off. Jumper them together and it runs all the time.

RandalJ · RandalJ's Garage

That thermostat tube (the end of which is in the evaporator) is an intregral part of the temp switch in the center console, and it leads to a bellows type thermostat in the switch housing. The bellows contracts or expands, depending on the temperature of the fluid inside of the tube.

If you are thinking of replacing the temp switch/tube assembly, be forewarned that the ones that are sold as genuine Porsche replacements do not fit the housing. I tried to replace mine last year, but had fitment problems. It was an extremely tight fit. I could have forced it in, but it would have distorted the plastic surround. But the main problem was that the spindle did not line up with the hole in the console. Not even close.

I had bought the replacement from Pelican, and had them verify the part number. I also called Porsche, and they provided the same part number, so I concluded that the new replacements were no good.

So, I ended up repairing the existing switch. The switch housing had partially come apart, interfering with the internal movement. It was fine after that. If you must replace, a used one from a salvage yard may be your only option, but kind of risky and a hassle to extract. Bypassing is another option, as mentioned above.

TCB · 09-05-2005, 05:58 PM

I don't know what element is in the tube, maybe a vacuum. Also what the tube is made of. I wonder if the tube could be resoldered. I didn't even think to check if it was copper, brass or aluminium. I had to trace a problem with my ac a while back and simply found a bad relay in the smugglers box but was concerned when moving the tube around. Does anybody know what is in the tube?

rjb · 09-06-2005, 05:21 PM

ok, sorry to keep asking the same question. Do I jumper the 2 green wires together and attach them to the switch or do I just jumper them together and leave them unplugged?

I went to the dealer and you were right, the new replacement switch didn't even come close and the dealer and no explanation since I brought the housing with me.

It seems one of them needs to be plugged in .

?????

chgrec · chgrec's Garage

You need the tube if you want the temp of the air to be variable...

The tube runs into the smugglers box and sends the current air temp back to the switch. It is basically a switch that then takes that temp reading and uses it to decide if the compressor clutch should kick engage or not. The green wires are simply the circuit that gets completed by the switch. If you connect them together, then the compressor clutch will always be engaged when the fan speed switch is on......

I bought the same switch from pelican a couple of months ago and it fit perfectly....tube & all.....

Chris

rjb · 09-06-2005, 06:18 PM

got it! So until i find a used replacement, I need to connect the 2 green wires together and I will get cold air, but how does it know to be all the way cold or not?

Will it automatically go to the coldest setting?

chgrec · chgrec's Garage

Yes, it will be on the coldest setting or always on....

the switch is simply an "on or off" switch based on the switch position & the current air output temp.....Once the temp reaches the requested level, the switch turns off the compressor. When the air gets warmer, it completes the circuit again and the compressor comes back on........

Our host sells the switch for $80

Chris

rjb · 09-06-2005, 06:58 PM

Thanks Chris for the input. FYI, they new switches are not the same as stock in size.

Thanks for all of the online support

chgrec · chgrec's Garage

Must be different on the 89....it fit perfect in my 84.....

And your welcome......anytime

Check with group911@aol.com He has lots of used parts and always gave me a good price....He is a pelican'er and his name is Bob

Chris

don911 · don911's Garage

I removed the ac a couple years ago and just last week removed the ac switches from the center console to do the rs carpet.
The switch is complete with the white wire thing. Yours for the price of shipping. The switches were working fine when removed.