Return-Path: Received: from fed1mtao08.cox.net ([68.6.19.123] verified) by logan.com (CommuniGate Pro SMTP 4.1) with ESMTP id 2505383 for flyrotary@lancaironline.net; Mon, 28 Jul 2003 12:45:33 -0400 Received: from smtp.west.cox.net ([172.18.180.57]) by fed1mtao08.cox.net (InterMail vM.5.01.04.05 201-253-122-122-105-20011231) with SMTP id <20030728164529.XAXU7156.fed1mtao08.cox.net@smtp.west.cox.net> for ; Mon, 28 Jul 2003 12:45:29 -0400 From: To: "Rotary motors in aircraft" Subject: Re: [FlyRotary] Re: starters and solonoids Date: Mon, 28 Jul 2003 12:45:30 -0400 MIME-Version: 1.0 Content-Type: multipart/mixed; boundary="----=____1059410730247_q8vBIe0brb" Message-Id: <20030728164529.XAXU7156.fed1mtao08.cox.net@smtp.west.cox.net> This is a multi-part message in MIME format. ------=____1059410730247_q8vBIe0brb Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Please correct me if I am wrong, but from the description, it sounds as though you have the following setup: Battery cable goes to contactor ("automotive: solenoid"); another cable runs from contactor output to starter solenoid. "Start" circuit energizes the contactor coil, closing high-current path to starter/solenoid. When start signal is removed, starter continues to spin. [||B||]-----------(C)-------------(S)-(M) The latter case is generally because the contactor has stuck "connected" (welded). If you want to prevent this from happening where you can't get out and disconnect it, wire two contactors _in_series_ with the start terminals in parallel, so that they are energized simultaneously. [||B||]---------(C)--(C)-----------(S)-(M) Now, if either contactor sticks, the other will still break the high-current circuit, and the motor will stop. BTW, back when I used to install Ford engines in strange places, I always took care to mount the contactor with the coil UP, so that gravity would work for me in opening the circuit, should the spring fail. Dale ------=____1059410730247_q8vBIe0brb Content-Type: text/html; name="reply" Content-Disposition: inline; filename="reply"

Bob:

Yes, but come to think of it, IF the Mazda solenoid is just an electrical contactor, not also a gear engagement mechanism (I don't know), you could bypass the original solenoid altogether.

Oh-oh, my book indicates you have to use both. The original engages the gear.

Bob Darrah

Yes it does engage the gear so I did wire the two solonoids in parallel on the activation wire but I disconected the battery cable from its' normal input side of the mazda solonoid and put it on the side that has the cable going to the motor. This way (I thought) no current is going through the mazda solonoid contacts. In spite of my being convinced this would solve the problem, I regret to say there is no change: stays running after starter switch opened.

So doesn't this have to mean that power is getting from the contacts to the coil of the solonoid???.

Peter

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