X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Tue, 12 Jan 2010 08:02:26 -0500 Message-ID: X-Original-Return-Path: Received: from web57506.mail.re1.yahoo.com ([66.196.100.73] verified) by logan.com (CommuniGate Pro SMTP 5.3.0) with SMTP id 4073644 for lml@lancaironline.net; Tue, 12 Jan 2010 06:48:16 -0500 Received-SPF: none receiver=logan.com; client-ip=66.196.100.73; envelope-from=casey.gary@yahoo.com Received: (qmail 26295 invoked by uid 60001); 12 Jan 2010 11:47:39 -0000 DomainKey-Signature:a=rsa-sha1; q=dns; c=nofws; s=s1024; d=yahoo.com; h=Message-ID:X-YMail-OSG:Received:X-Mailer:References:Date:From:Subject:To:In-Reply-To:MIME-Version:Content-Type; b=aMg/jWNm5BIB7MBdxJm5Aa9xaCFgXJKNInN7BuXq+9WADPURZdHmD5G9N4fZ4d49opdDfYnoIAxyzl3KtApcIsZrRkZhu+6hbphMhnJ12QlWyOxghPLdnFGvI2NXx4DusweZ5NH4W0Gd4ROt7Fpg/47UQJUJEzZY4B+BjL/uPJk=; X-Original-Message-ID: <462850.25431.qm@web57506.mail.re1.yahoo.com> X-YMail-OSG: uRzc0pYVM1mfBXgaoXLCky_21sxJUldVAss.omcQ_5VaouXOyjzza6oITwSkRE4CTZ1dyZABZtla5V0AoFxfXQ.r5FObWUsgwmj37s1DflUF04r2cnt7.Guo8gBt4MMOF779jCFknAdBkAqqcopYsrpKQ8eDumKb.u3K3.mIEyCobdzK_1SvEYvBk.JK9ZYcqDnrFg8.K5rJcqLqpvZitq1dbuDYF1IK0UBZWLaLTDVqEotBAsXZp74IsFVKLS6ZX03aI.taKxJeMh8- Received: from [97.122.179.31] by web57506.mail.re1.yahoo.com via HTTP; Tue, 12 Jan 2010 03:47:39 PST X-Mailer: YahooMailRC/240.3 YahooMailWebService/0.8.100.260964 References: X-Original-Date: Tue, 12 Jan 2010 03:47:39 -0800 (PST) From: Gary Casey Subject: Re: voltage variation X-Original-To: Lancair Mailing List In-Reply-To: MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="0-533403549-1263296859=:25431" --0-533403549-1263296859=:25431 Content-Type: text/plain; charset=us-ascii Randy, You'll probably get more expert answers than mine, but here is what I would do if I didn't have an oscilloscope handy: Measure the voltage on the field wire from the regulator to the alternator. With no load and the battery voltage over 14 it should read a low voltage - 2 or 3 maybe, but not zero. When you add load it should go up and with the battery voltage pulled down to 12.5 it should read full battery voltage. If the field is full on and the voltage is still low there must be a problem with the alternator. But before changing that I would check all the electrical connections between the alternator and battery, especially the alternator ground. That would mean loosening and retightening all the bolts including the alternator mounts. Being bolted to the engine usually provides an adequate ground, but is there a chance that it is not? Gary Just a quick question from a peon 235 driver, I am running a suzuki 55 amp alternator which i have removed the voltage regulator. I am using the old ford style regulator mounted on the firewall. 3 weeks ago I was taxiing in and my voltage dropped so low 10v that my dynon glass panel went black and then came back on. I turned everything off and the voltage went to 14.7. Turn on the landing lights and loaded it up and it was back to 10 v or so. I replaced the voltage regulator as that was a cheap fix. It is still happening. The voltage hovers around 14.5v with little load and drops to 12.5 or so with a load at cruise. Is this just a simple case of the alternator needing rebuild. It has around 400 hours or so.. Randy Snarr N694RS 235/320 --0-533403549-1263296859=:25431 Content-Type: text/html; charset=us-ascii

Randy,

You'll probably get more expert answers than mine, but here is what I would do if I didn't have an oscilloscope handy: Measure the voltage on the field wire from the regulator to the alternator. With no load and the battery voltage over 14 it should read a low voltage - 2 or 3 maybe, but not zero. When you add load it should go up and with the battery voltage pulled down to 12.5 it should read full battery voltage. If the field is full on and the voltage is still low there must be a problem with the alternator. But before changing that I would check all the electrical connections between the alternator and battery, especially the alternator ground. That would mean loosening and retightening all the bolts including the alternator mounts. Being bolted to the engine usually provides an adequate ground, but is there a chance that it is not?

Gary

Just a quick question from a peon 235 driver,

I am running a suzuki 55 amp alternator which i have removed the voltage
regulator. I am using the old ford style regulator mounted on the firewall. 3
weeks ago I was taxiing in and my voltage dropped so low 10v that my dynon
glass panel went black and then came back on.
I turned everything off and the voltage went to 14.7. Turn on the landing
lights and loaded it up and it was back to 10 v or so.
I replaced the voltage regulator as that was a cheap fix. It is still
happening. The voltage hovers around 14.5v with little load and drops to 12.5
or so with a load at cruise.

Is this just a simple case of the alternator needing rebuild. It has around
400 hours or so..

Randy Snarr
N694RS
235/320

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