There is a white plastic sheath over a hollow copper tube that used to connect to the top my AC switch. It has snapped off right where it connects to the switch. I think it is a thermostat. Can it be repaired or must I find a new switch? Or is there some other work around? The rest of the AC system is in working order, but it won't work without this connection.

 

The copper tube - is a capillary tube that touches the low side pipe under the dash. The twist **** is kind of like a temperature control, the further clockwise , the colder the freon is before switching the power to the compressor off. If the theremostat does not connect the two green wires with no capillary tube - jump them together to supply power to the compressor all the time - if it gets too cold (in a 240 in the summer?) the compressor will not turn off - that could be a problem on long trips (in an old 240?) but in stop and go traffic and around town i doubt if the refrigerant would ever get too cold!

 

Welcome to VF DMon707
It needs to be replaced to work properly. What model do you have ?

 

1984 Volvo 240 Switch A/C Temp Gauge 83/90. They don't sell the part anymore. None to be found at nearby wrecking yards. Proposed solution is a rocker switch next to thermostat dial for green relay wire.

I'm ready to wire in the rocker switch, which would ideally fit into the 2"x1.12" slot next to the dead thermostat dial. Trying to find a rocker switch that will adapt to that big a slot is proving to be frustrating, since the last thing switch shoppers want, evidently, are dimensions. Plus, I assume, it must be a dc switch. Rocker is optional, but it seems like the most convenient type of switch, since it's what Volvo used on all its other dashboard switches, none of which can I find for sale online either.
Thanks!

 

Do you still have an R12 York Compressor? Just curious....

 

Try Voluparts.com in Atlanta for the real thing 404-352-3402 - If the twist style thermostat is not available - you could use the rocker switch style used in 91-93 240s. (without a thermostat function)
Several other simple on/off rocker switches were used in those 240s for other functions - any of those would work - rear defrost, fog light, etc (except for the emergency flasher switch) They just won't have the blue lens used in the ac rocker.

If you use a rocker switch without a thermostat - the system could freeze up at highway speeds or cooler temps - which can destroy the compressor -

 

The AC compressor is the same as it was in 1988 when I purchased the car. The whole system has never had a breakdown of any kind until the thermostat tube snapped off. But then, living in San Francisco, the AC has been used only on long trips out of town.

 

Voluparts did the trick! Thanks, Hoonk.

I now have the part and am ready to switch it out for old one, but it's always something. When I'd despaired of finding the part, I had prepared everything for a simple on-off rocker switch, which means I removed the wiring from the old part and clipped off and discarded all of the clips. That's what happens when I try to stop hoarding. Now I need to find a wiring diagram (or some guide) for the AC control switch. I seem to recall that both green wires attached on one side (right side from the front) and the red wire and red and white wire attached on the left side with a funny little red wire connection from one place to another on the left side. I can experiment, but I don't want to short something out. The red wire is apparently the power and the red and white, I imagine, is the ground. Then the other issue is laying in the thermostat coil. It has to go through into the engine area, I believe. Be nice to have a diagram. I've tried to find one on this site, but that's a difficult search.

 

The green wires are in series with the thermostatic switch. Maybe from the relay to the switch, then to the low pressure switch on the drier then to the compressor. The thermostat simply interrupts the power to the compressor. (on the green wire)

The thermostatic tube - attaches to the low side pipe under the dash above the passengers feet. A clamp there with some ac insulation tape over the tube. Insulation tape is needed because the cold AC pipe will cause condensation - and that will drip onto your dates feet - She/he might not like that sensation.

Not sure about the other red/white colors (it's been a long time since I've look at those) - might be to a bulb that illuminates the switch (with the dash lights) Are there other red/white wires going to the other console illumination bulbs?

 

Thanks (again) for the tip. So you think the juice in the green wire not only activates the compressor, but also powers the thermostat? There's no light bulb or other illumination involved in the dial switch assembly, but I'll look for other red/white wires behind the dash.

 

The thermostat does not require power - two green wires connect to the micro switch - 1 Green wire ends up next to the compressor, and a harness with two green wires goes across the top of the radiator to the low pressure cut off switch on the drier and back to the same area. That switch prevents the compressor from self destructing if the system goes empty and the compressor is energized.

 

So the micro switch is presumably the smaller black box? When I was testing the wires for a rocker switch I discovered that, when joined, the green wires operated the compressor. I'm guessing that, so long as there is not a second power source, I can experiment with the other wires and just see what works. Thanks!

 

Yes, both green wires to the microswitch.

Does the red/white wire go to the bulb that illuminates the light bar above the rocketr switches? Like the wiring/bulbs for the fan switch and heater temp illumination?

 

There is no illumination for the rotary A/C switch, but I'll look into that.

 

Correct, there is no bulb holder in any of the switches in that row for illumination. (for the hazard sw there is a bulb in the bottom of the switch that flashes through the red lens when on, a front fog light switch has a green lens and a bulb in the bottom when on, a 91-93 ac switch has a blue lens and a bulb in the bottom when on, rear defroster sw has a bulb in the bottom when on, etc.....)

The illumination for that row of switches comes from a plastic "light" bar mounted above them with a bulb stuck in the middle. Same bulb holder and wiring as the two bulbs/holders for the fan switch and heater slide illumination.

Those 3 bulbs are the only illumination for the center console switch area.

 

The twist **** is kind of like a temperature control, the further clockwise , the colder the freon is before switching the power to the compressor off. If the theremostat does not connect the two green wires with no capillary tube