X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Mon, 30 Jan 2006 01:16:14 -0500 Message-ID: X-Original-Return-Path: Received: from s-utl01-dcpop.stsn.net ([72.255.0.201] verified) by logan.com (CommuniGate Pro SMTP 5.0.7) with SMTP id 960215 for lml@lancaironline.net; Sun, 29 Jan 2006 22:08:11 -0500 Received-SPF: none receiver=logan.com; client-ip=72.255.0.201; envelope-from=rpastusek@htii.com Received: from s-utl01-dcpop.stsn.net ([127.0.0.1]) by s-utl01-dcpop.stsn.net (SMSSMTP 4.1.2.20) with SMTP id M2006012922071900166 for ; Sun, 29 Jan 2006 22:07:19 -0500 X-Spam-Status: No, hits=0.0 required=9.9 tests=ALL_TRUSTED: -2.867,AWL: 0.423,BAYES_00: -1.665, SARE_RECV_ADDR: 0.027 X-Spam-Level: Received: from boblaptop2 ([10.16.167.2]) by s-utl01-dcpop.stsn.net for lml@lancaironline.net; Sun, 29 Jan 2006 22:07:17 -0500 From: "Robert R Pastusek" X-Original-To: "Lancair Mailing List" Subject: RE: [LML] Alternator troubles X-Original-Date: Sun, 29 Jan 2006 22:08:43 -0500 X-Original-Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook IMO, Build 9.0.2416 (9.0.2910.0) Importance: Normal X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2600.0000 In-Reply-To: Steve Reeves wrote: About 3 weeks ago I noticed for the first time ever a brief overvoltage problem.... I cycled the switch and the alternator came back online. A few more times the discharge light would come on, then start "charging" again with no input from me.... Steve, I'll leave the recommendation about alternator size to others, but your problem sounds like a classic case of defective wiring/loose connection to me, most likely in the ground side of the system, or anywhere in the voltage regulator part of the circuit. Bob Nuckols' Aero Electric Connection, www.aeroelectric.com/ has an excellent chapter on alternators/charging circuits. Well worth the read, and much better trouble shooting details than below, but you need to buy his "Aero Electric Connection book (recommended) to have access. If you elect not to buy/read Bob Nuckols, start by looking for frayed, damaged, or pinched wires, and check every terminal/connector in the circuit. Corrosion and/or loose/broken wires are often culprits. Hate to recommend this, but another area is a broken ground wire inside the alternator, especially if it has a built-in voltage regulator. The third likely culprit is the voltage regulator itself. Even if it's not bad now, continued operation under the conditions you describe will likely fry it in short order. This is to say, if you find a loose connection/broken or frayed wire, you can fix it and assume that as the problem if this restores normal operation. If, however, you replace the voltage regulator without checking out the wiring, don't be surprised if the condition recurs in short order... An easy test is to replace the regulator and then the alternator in turn--after checking the wiring and finding no faults. If you don't have access to "loaners" for testing, these can be bench tested for a nominal charge at a good repair facility, or at a local auto generator shop (assuming an experimental aircraft). Hope this helps! Bob Pastusek