A/C button - retrofit?

[andrewm]

I'm getting real tired of my AC button failing in one way or another - anyone every devised a better solution? I've been toying around with the idea of wiring in a new button - one that does recirc and A/C and calling it a day.

And...I've got a thing for toggle switches.

[jlevie]

Are you have new OE switches fail? That would make me think that something controlled by the switch is drawing excessive current. If you have been using used switches, get a new OE part, like from your dealer.

[andrewm]

Two used ones, one broke the tabs - this one the button is now staying down, but the contact is off/on. Gotta pull the switch out and fiddle with it, and then the AC kicks back on.

[jalopi]

Nothing wrong with a toggle switch IMO. Might look kinda ghetto, but it'll work. Just make sure you get a toggle switch good for the amperage going through the factory switch... a 20 amp toggle will probably be fine, but check just to make sure.

[barbierij]

^makes me wish I had a rear wheel drive E30!

[MR 325]

Seems pretty silly to hack up your wiring for something that can easily be replaced with either a good used part (a million of them out there) or a brand new OEM part from BMW.

[andrewm]

Well, if I did it - I would make it look good and I doubt the actual switch is my issue right now.

I tore this one apart to try and figure out - looks like the AC fan is kicking on, but not the compressor. Does anyone know on the AC button, there are 8 "tongues" - four for each button.

The A/C button has four, I need to figure out which tongue does what.

[jlevie]

The first check should be to see if power is applied to the pressure limit switches when the A/C is engaged. If the car the original A/C dryer it will have a low and a high pressure switch. The high pressure switch receives power from evaporator temperature control when A/C is engaged and passes that onto the low pressure switch which feeds the compressor clutch. All three have to work for the compressor to run.