Electrical people - relocating pressure switches in a climate control uint???

quantum · 02-01-2008, 10:44 PM

Hi all,

This is the first time I have come across this, a little help please?

This climate control unit is out of a 2002 Deville (my future car). I took apart the whole thing, and found out that they are just pressure switches mounted to a thin PCB film. The big switches that work the controls actually press into a rubber plate with a dimple on the back, which in turn "presses" the switch.

If there is a way to relocate the buttons and still control the climate, it opens up some possibilites for me with regards to monitor size. So, I was wondering, with the exception of mini linear actuators, is there any other way to send a signal to the switch?

*NOTE* to TurboCad, look familiar?

TY!

blk02si · 02-02-2008, 03:08 PM

You just need to close the circuit path.

Easiest way I can think of is soldering some leads to that printed circuit film and put monetary switches on the leads.

quantum · 02-06-2008, 11:52 PM

Thanks for the info blk02si. Any other suggestions from the masses?

Now, the big question...this looks a little out of my league, some of those traces are REALLY thin. Plus, I've only soldered big stuff, never a film like this.

Maybe some of you skilled individuals with the right tools can offer some guidence or even want to make a few bucks??

Thanks!

FordNoMore · 02-07-2008, 03:11 AM

The masses say: blk02si is correct!

See the squiggled bare traces on the board where the switches are? All the "pressure switch" is is a conductive piece of rubber (or plastic with conductive paint underneath, or something like that) that mashes against the circuit board and bridges between the two contacts when you press on it. Nothing more magic than that.

If you end up doing the soldering yourself, rather than try to solder onto the tiny little squiggly traces that are much too close together for comfort, try scraping off some of the green soldermask a little farther back where the traces are bigger and more accessible, and solder wires there.

Good luck!

(And if you're around San Diego, I may be able to help.)

FordNoMore · 02-07-2008, 03:20 AM

Oh, and another tip if you didn't already know: Each switch has two contacts - one that's specific to that switch, and one that's common to all of the switches. (You can tell by following the traces on the board, or checking continuity with a multimeter.) You only need to connect one wire to the board for the common - so that cuts your soldering job about in half if you were thinking you had to connect two wires to the circuit board for each switch. (From the picture, looks like 12 buttons, so you'll need 13 wires soldered to the board.)

quantum · 02-11-2008, 11:14 PM

Thanks for the tips, FordNoMore, greatly appreciated!

I just may take you up on your offer one day in the near future.

pir8radio · 03-04-2008, 09:12 AM

I would not solder to the film, but to where the film plugs into the car or other PC board. Hang on to the film. for when you trade your car in. :-)

MindDrive · 03-19-2008, 10:17 AM

what your doing is very similar to what ive done with a keyboard circuitboard... and yes an ohm-meter is the ONLY way to do it without loosing 99.3% of your hair

if you look in the fantabulous paint pic i made up, youll see that if anyone uses a keyboard circuit in this manner, there are LOTS of "shared" circuits, not just a single common but many, dunno how caddy's have the climate control, but the work you did on your caddy has definately given me some great ideas

good to see people not afraid to rip into luxury cars ^_^

*edit*
i just noticed that the circuit you have shown there has surface mount resistors on it, which means that they might not only have a common signal, but the amount of voltage might also play a role with making aftermarket connections/buttons etc.... if thats the same as the finished dash console as in your sig, i'd keep an eye on it and the fuses real close like, replacing that film and/or the board it connects to probably wont be a nice thing to try and find

Civic Modz · 07-02-2008, 09:46 PM

Why not try to interface the buttons of your climate with a serial/usb port of your pc so you can control everything via touch screen. For the times when you PC is not running you can have a back up remote. So you can relocate your original climate anywhen and then not have to deal with finding a space to mount your buttons. I say this with confidence since I have done it myself. This is the most "cleanest" way i think. The only problem is that i have not much experience in making applications.