audi a4 cabriolet remote top operation

I am installing a compustar pro alarm/remote start in a 2003 audi a4 cabriolet. I am trying to hook up the convertible top to the alarm so I can remotely open and close it with the auxiliary channels. The interior switch seems to be controlled by the bus system, and is not easily hardwired. The motor is operated by a controller, and doesn't look like something I could safely wire a DEI 529t with. I'm sure it can be done because the smarttop controller by mods4cars can operate it via the factory remote. Anyone ever do this, or have any ideas. Thanks!bzzzzttttt

no way to do it...its can bus all the way, could try to find the actual motor wires to the top but you still wouldnt have the windows crack when the tops going down so i would not recommended it

I know on earlier pre-CAN versions, say up to 2001, you could simply extend the lock pulse as in the 3 series BMW. Effectively you have to power up the ignition and then possibly feed the switch. 

Sorry to post again on this subject but I was just looking this up on Autodata (do you have it in the US?).  It lists roof open and close relays behind the trim, right hand rear in the trunk. No actual wiring, just component positions.  You could do it across both relay motor outputs because that way it emulates a switch using a 529t.  Just go to the trunk and find the two motor wires.

Wouldn't there be a latch at the windshield that you'd have to deal with, in addition to the power top motor wires? Or does applying power to the motor wires release that as well?C Renner's Auto Electronix

My service is cheap, quick, and good - pick any two

Not sure, I think it's like Porsches and later, about 97 on 3 Series, no mechanical latch. Wish I could see a wiring diagramme, might be a way to "spoof " the processor that controls it.

Thanks for the replies! The top is fully automatic so there are no manual window latches. I think that I might just be able to power the relays with a timed output, but I'm not sure. I think that there might be different mechanisms for the boot lid and the top (maybe even the automatic windshield catches). There are quite a few wires, so I am going to get a helper to operate the top while I check the wires. Of course some of them are in the trunk, which has to be closed for the top to operate. And, of course, Metz has a good point that the windows wouldn't roll down before operation as required.bzzzzttttt

Frankly unless you can obtain a circuit diagramme let alone follow it (no insult intended) the method you're going to use is the only way. I suggest a collection of 528ts or similar. You need a control that brings on window drop prior to roof close.  The trouble is the factory could do this via the closing relay or earlier in the chain via the processor. we just don't know.

I have a pdf wiring diagram that should help but i can't attach it shoot me a pm with you email address and i'll send it over

scratch that, i uploaded it to the downloads section https://www.the12volt.com/installbay/downloads.asp?srch=all&term=audi+a4