Troll Hunter Posted March 17, 2011 Share Posted March 17, 2011 Can somebody who has done this before please advise me? I've a VDO tacho, but no installation instructions. I believe that a signal can be taken from the alternator output. I've a standard 300 Tdi and alternator, but where do I take a signal from, please? At the tacho, there are three connections, apart from the light connections. These are marked: 2, + and -. (The location 1 does not have a connector fitted to it.) I'm assuming that live and earth are connected to the + and -, but what goes to 2? Is it a direct feed from the alternator, or should there be something between the alternator and tachometer, e.g. a resistance? Also, staying with the tacho, there are three small switches recessed in the body. What are they for, and what positions should they be set to, please? Many thanks, in advance, for any help with these. Mike Quote Link to comment Share on other sites More sharing options...
western Posted March 17, 2011 Share Posted March 17, 2011 connect Tacho terminal marked '2' to the 'W' terminal on Alternator connect a ignition controlled 12volt feed to tacho terminal marked + [positve] connect tacho terminal marked - [negative] to earth tacho light to existing guage lighting set the 3 slide swithes [outers] up & centre down. this should give to a idle reading of 750 to 800rpm & max revs [vehicle stationary out of gear] of 3850 to 4000rpm. if you do a search for 'rev counter' there's lots of top info about fitting/connecting & photo's. Quote Link to comment Share on other sites More sharing options...
Troll Hunter Posted March 18, 2011 Author Share Posted March 18, 2011 connect Tacho terminal marked '2' to the 'W' terminal on Alternator connect a ignition controlled 12volt feed to tacho terminal marked + [positve] connect tacho terminal marked - [negative] to earth tacho light to existing guage lighting set the 3 slide swithes [outers] up & centre down. this should give to a idle reading of 750 to 800rpm & max revs [vehicle stationary out of gear] of 3850 to 4000rpm. if you do a search for 'rev counter' there's lots of top info about fitting/connecting & photo's. Many thanks for your reply, Western. However, referring to the photo of the back of my alternator, in my original post, which is the W terminal, please? Having searched, I've found the following, which you posted in december 2010 in response to a V8 alternator query: Posted 04 December 2010 - 12:05 PM your alt. may already have a 'W' terminal under a rubber cover, if not you can fit a feed wire from one of the static windings bolts IIRC. Is my alternator one of those without a W terminal, and if so, which bolt do you suggest that I take a signal from, please? Mike Quote Link to comment Share on other sites More sharing options...
western Posted March 18, 2011 Share Posted March 18, 2011 if your Alt doesn't have a external, W connection, Yes you can fit a cable & terminal to any of the AC static windings to make it all work. see Red90's reply/photo in this these links http://forums.lr4x4.com/index.php?showtopic=3026&hl= http://forums.lr4x4.com/index.php?showtopic=9408&hl= http://www.reedx.net/landrover/mods/revcounter/index.htm Quote Link to comment Share on other sites More sharing options...
Troll Hunter Posted March 21, 2011 Author Share Posted March 21, 2011 Western, as usual, you've been there, dunnit, and are happy to help the rest of us find our way about. I followed the links, and the links in links, and have now got my tacho working. Many, many thanks. Mike 1 Quote Link to comment Share on other sites More sharing options...
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