From ti@bazooka.amb.org Wed Sep 15 11:04:06 1993 Return-Path: Received: from ns1.mke.ab.com by tinman.mke.ab.com (4.1/SMI-4.1) id AA27251; Wed, 15 Sep 93 11:04:06 CDT Received: from Sun.COM by ns1.mke.ab.com (4.1/SMI-4.1) id AA25358; Wed, 15 Sep 93 11:04:45 CDT Received: from snail.Sun.COM (snail.Corp.Sun.COM) by Sun.COM (4.1/SMI-4.1) id AB01280; Wed, 15 Sep 93 09:04:36 PDT Received: from East.Sun.COM by snail.Sun.COM (4.1/SMI-4.1) id AA01501; Wed, 15 Sep 93 09:04:34 PDT Received: from suneast.East.Sun.COM by East.Sun.COM (4.1/SMI-4.1) id AA23217; Wed, 15 Sep 93 12:04:32 EDT Received: from aries.East.Sun.COM by suneast.East.Sun.COM (4.1/SMI-4.1) id AA00129; Wed, 15 Sep 93 12:04:26 EDT Received: from East.Sun.COM (east.East.Sun.COM) by aries.East.Sun.COM (4.1/SMI-4.1) id AA08658; Wed, 15 Sep 93 12:04:19 EDT Received: from Sun.COM (sun-barr.EBay.Sun.COM) by East.Sun.COM (4.1/SMI-4.1) id AA23198; Wed, 15 Sep 93 12:04:21 EDT Received: from sgiblab.sgi.com by Sun.COM (4.1/SMI-4.1) id AA01206; Wed, 15 Sep 93 09:04:10 PDT Received: from bazooka.amb.org by sgiblab.sgi.com via UUCP (920330.SGI/911001.SGI) id AA11625; Wed, 15 Sep 93 09:04:08 -0700 Received: by bazooka.amb.org (Sendmail 5.59/AMB-1.2) id AA09257; Wed, 15 Sep 93 08:48:41 PDT From: ti@bazooka.amb.org (Ti Kan) Message-Id: <9309151548.AA09257@bazooka.amb.org> Subject: Re: Central locking To: alasdair%sdlunix@Sun.COM (Alasdair Mackintosh), quattro@aries.East.Sun.COM (Audi Mailing List) Date: Wed, 15 Sep 1993 08:48:40 -0700 (PDT) In-Reply-To: <9309150818.AA20944@sdl.ug.eds.com> from "Alasdair Mackintosh" at Sep 15, 93 09:18:42 am X-Mailer: ELM [version 2.4 PL22] Content-Type: text Content-Length: 2539 Status: RO Alasdair Mackintosh writes: > I have a early 1986 model Audi 80 ( Audi 4000 in the US, I believe) whose > central locking recently died on me. The pump that drives the system is > still fine - I connected the battery to its terminals, and the locks opened > and closed. This suggests, even to inept electricians like me, that there's > something wrong with the wiring. (It isn't the fuse. Life ain't that simple.) > > Before I start to trace through all the wiring, I was wondering if anyone else > has had a similar problem, and could give me some clues as to where I should > start looking. The Audi central locking system is actually extremely simple as far as electrical wiring is concerned. The only wiring is to the driver's door and to the pump itself. There is no wiring to the other doors, only air tubes. The driver's door has a plunger-type switch that detects whether you are locking or unlocking the door (it is a single-pole double-throw design). The central contact of the switch is wired to a fused 12V line on the fuse relay panel, and the two other contacts to the central locking pump. The pump itself has three electrical connections, two of them from the aforementioned door switch, and one to ground (tied to the body in the luggage compartment). That's all! Before you dig into the wiring, verify that the fuse is not blown. On U.S. 1986 4000 models, this is fuse #19 (10 Amp) on the fuse-relay panel. If the fuse is good, then use a voltmeter to measure the terminal 1 and terminal 3 on the central locking pump. You should have 12 volts on one of them with the driver's door in the locked position, and 12 volts on the other when the door is unlocked. If you only get 12 volts on one of them but not the other as you lock/unlock the door, then the culprit can be either the wire from the plunger switch to the pump, or the switch itself. If you don't get 12 volts on both lines then the problem is likely to be either the switch or the 12 volt line from the switch to the fuse/relay panel. Carefully remove the inside door panel and remove the switch and test it with a continuity tester. If the switch is good, then the wiring is bad. Are you getting 12 volts on the line (typically a red/black wire) at the switch contact #2? Good luck... -Ti -- /// Ti Kan vorsprung durch technik /// AMB Research Laboratories, Sunnyvale, CA. USA /// ti@amb.org ////// ...!{decwrl,synopsys,tandem,tsoft,ultra}!sgiblab!bazooka!ti /// ...!uunet!bazooka!ti