tuko Posted May 3, 2009 Share Posted May 3, 2009 I would like to install a ammeter gauge that I have from an early RRC. (the round 50 to 50 gauge) Going through the WSM for RRC's the ammeter is wired in between the starter switch and the start motor. Too simple right, but on my diesel conversion I have a start relay between those tow components. I'm sitting here and wondering do I wire the gauge in before the relay or after? Or can it be wired into my vehicle?? Attached is an image of my wiring diagram for my hybrid.....How would I wire in the gauge if at all? Cheers, Todd. Quote Link to comment Share on other sites More sharing options...
western Posted May 3, 2009 Share Posted May 3, 2009 better to have a battery condition also known as a voltmeter on a modern vehicle. ammeters were used on dynamo fitted vehicles, not alternator fitted vehicles. a ammeter will need large diameter cables just to carry the alternators output current. Quote Link to comment Share on other sites More sharing options...
landmannnn Posted May 3, 2009 Share Posted May 3, 2009 Agreed, either bin it or 'bay it. Quote Link to comment Share on other sites More sharing options...
David Sparkes Posted May 3, 2009 Share Posted May 3, 2009 To expand a bit on Western's reply (I'm not disagreeing with it); with the engine running and all systems working properly, the Ammeter is showing the charging current going into the battery. Once the initial recharge has taken place this could be about 5 amps. With the scale of a 50-0-50 ammeter the needle will have moved it's own width (approximately). This isn't a very clear indication that all is well. At this point the alternator could be pushing out 30 amps in order to run the complete electrical load, but the ammeter isn't intended to show that. Stall the engine and the ammeter will swing into the discharge side to show the 30 amp battery discharge that is taking place. Cars fitted with alternators were expected to have a larger electrical load, so the 30-0-30 ammeter was changed to 50-0-50 to cope with this higher load, should 'everything' be switched on while the engine wasn't running. Minimising voltage drop is important if the battery is to be maintained in a fully charged condition, so (apart from the cost of copper) you can see why no-one thinks it a good idea to run long cables between the battery and the alternator. If you want to persist, there is no single wire in your diagram that you can cut to insert the ammeter. You need to remove the brown wire from the starter motor and re-terminate it on the fuse box, on the same terminal that currently carries the brown wire from the battery. There are now two wires on the same fuse box terminal. 'Cut' the brown wire from the battery to the fuse box and insert your ammeter. It doesn't matter which way round, because getting it wrong will merely cause the ammeter to show charging when it's discharging, and vice versa. The effect is that when the alternator is carrying all the electrical load, it is feeding into the fuse box, with the charging current going 'UP' via the ammeter (on your diagram). When the battery is carrying all the electrical load the current is flowing 'DOWN' via the ammeter to the fuse box. It will do this for instance when the glow plugs are heating, before you start the engine, and it will show you if one plug fails completely, as you will get less current flow than you are used to seeing. Of course, plugs rarely fail completely like that, they just take a little less current, and don't get as hot. With this change in mind you can now look at your vehicle and see how much extra wire you need. HTH. PS I have to say, I would not have attempted an explanation of how to wire in an ammeter if you hadn't posted the wiring diagram, so that was definitely a useful bit of self help there by you, (assuming the explanation is worthwhile!!!). Quote Link to comment Share on other sites More sharing options...
tuko Posted May 3, 2009 Author Share Posted May 3, 2009 Thanks for the replies guys, including the educational reply David. To be honest I didn't know that it was specifically made for dynamo vehicles as it did come from a 70's Range Rover 2 door. The old RR, I removed all the original round gauges and was thinking that I could use a few. Well at least I can still use the clock. Cheers, Todd. Quote Link to comment Share on other sites More sharing options...
western Posted May 3, 2009 Share Posted May 3, 2009 if you still have the old RR might be worth looking at the wiring to see how LR did it. Quote Link to comment Share on other sites More sharing options...
siggy Posted May 3, 2009 Share Posted May 3, 2009 Although keep the ammeter for troubleshooting circuits etc and other faults Quote Link to comment Share on other sites More sharing options...
tuko Posted May 3, 2009 Author Share Posted May 3, 2009 Sorry Ralph, the gauges came from a parts RR that a friend was scrapping. Siggy, man it's been a while since I utter that name. Nice to see you again and nice to see that you did make it across the pond. Get a hold of Andrew in London, he's one of the admin guys from OVLR and is active in your/his area. Cheers, Todd. Quote Link to comment Share on other sites More sharing options...
western Posted May 3, 2009 Share Posted May 3, 2009 Sorry Ralph, the gauges came from a parts RR that a friend was scrapping. . oh well, blown that idea clean out. Quote Link to comment Share on other sites More sharing options...
tuko Posted May 3, 2009 Author Share Posted May 3, 2009 oh well, blown that idea clean out. Ralph, I seem to remember having or seeing some wheres an optional parts catalog for early Range Rovers and it had complete diagrams in it.......Of course not the slightest where it was Quote Link to comment Share on other sites More sharing options...
siggy Posted May 4, 2009 Share Posted May 4, 2009 ONly in london on weekends and have been meaning to Quote Link to comment Share on other sites More sharing options...
hattymender Posted May 4, 2009 Share Posted May 4, 2009 Shunts? I've an ex military ammeter somewhere that uses a shunt (which I've lost). If I remember properly the shunt, which looks like a big fuse, goes in the main power line. Brown in the above diagram. It's matched to the ammeter, so a 50 amp ammeter needs a 50 amp shunt. The ammeter itself only uses lightweight wiring 'cos it's just measuring the voltage drop across the shunt, about .75V at full load if I remember the numbers properly. Much tidier installation. But still doesn't tell you much of use, which is why it's in the parts bin. Quote Link to comment Share on other sites More sharing options...
western Posted May 4, 2009 Share Posted May 4, 2009 Ralph, I seem to remember having or seeing some wheres an optional parts catalog for early Range Rovers and it had complete diagrams in it.......Of course not the slightest where it was might be in here 1987 on http://www.islandrover.is/gamli/islandrove..._electrical.pdf Quote Link to comment Share on other sites More sharing options...
tuko Posted May 6, 2009 Author Share Posted May 6, 2009 Going back to my treasure trove, I dug deep in the parts bin and found another gauge that I can use on the landy. From an early series 2 I removed the voltage gauge and installed it in the place of the now un usable water temp gauge. Works a treat. Todd. Quote Link to comment Share on other sites More sharing options...
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