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Join Date: May 2004
Location: Dublin, Ireland
Posts: 49
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Speedo Sender Woes
Hi All, have a dead speedo in my '76 Carrera, took out the sender and I'm getting continuity all the time across the terminals
 I tried waving a magnet across it to no avail... Am I right in thinking that it's a goner? (Don't want to buy a new one unnecessarilly) Thanks! Warren McAllister
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'76 Carrera 3.0 '02 Mercedes Benz E200K Bianchi (Road) Cannondale F800 (MTB) |
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05-08-2004, 11:48 AM
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Location: South Elgin, IL
Posts: 1,084
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I believe the sender is a coil and it picks up the mags on the transmission and creats a small voltage like a generator. So it would read continuity.
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Mike Minister of YEP 1986 targa 3.2 " RED" 1970 Little T (Wife’s car) Gruppe B # 917 |
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05-08-2004, 12:10 PM
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Location: TX USA
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Quote:
WRONG!!! The speedometer sensor is a magnetic reed switch with normally open contacts, and the switch contacts close and open in response to the eight ceramic magnets on a carrier wheel inside the transaxle case. The factory service manual specifically says to test for eight switch closures per revolution of the ring gear!
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Warren Hall, Jr. 1973 911S Targa ... 'Annie' 1968 340S Barracuda ... 'Rolling Thunder' |
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05-08-2004, 12:17 PM
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Location: Cornwall-on-Hudson, New York, USA
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Sounds like it's bad. You should get continuity only if you put a magnet on it to close the switch.
Stephan
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Stephan Wilkinson '83 911SC Gold-Plated Porsche '04 replacement Boxster |
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05-08-2004, 02:23 PM
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sorry about the bad info and I'll be more careful
to check my info before I respond in the future
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Mike Minister of YEP 1986 targa 3.2 " RED" 1970 Little T (Wife’s car) Gruppe B # 917 |
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05-08-2004, 05:36 PM
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Location: Dublin, Ireland
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Thanks for your help everyone! - Warren
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'76 Carrera 3.0 '02 Mercedes Benz E200K Bianchi (Road) Cannondale F800 (MTB) |
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05-09-2004, 03:43 AM
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