Joined: Aug 2017 Posts: 861 Threads: 74
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Can anyone tell me which wires go to which terminal on an ammeter ('37 Ruby, positive earth). I took it out 6 month ago and have lost the notes I made!
I have:
white and black which I think is from the starter and must be -ve
thin red for the instrument lights which I assume to be -ve
also heavy black wire which I'm guessing is +ve and...
heavy purple and white wire, both of these last two disappear into the loom.
The wiring diagram shows one wire going to the centre terminal of the lighting /ign switch but on mine this is a blank terminal.
Peter.
Joined: Aug 2017 Posts: 984 Threads: 6
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Location: Scottish Borders
You could try wiring a bulb from battery +ve through the ammeter to battery -ve. That would tell you which way round it goes.
Jim
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I know which way the ammeter goes but just wanted to be clear which side the purple/white wire and the black wire should be connected? I suppose I wasn't expecting to see a black wire.
Peter.
Joined: Aug 2017 Posts: 984 Threads: 6
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Location: Scottish Borders
I would expect that one side of the ammeter connects directly to the battery. The other side feeds components on the car. Thus the measuring the resistance between each ammeter wire and the batter cables should reveal which is which.
Both the battery and ammeter should be disconnected while measuring resistance.
The feed side is battery positive if negative earth and vice versa.
Jim
Joined: Aug 2017 Posts: 741 Threads: 8
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Location: N W Kent
One of the "spare" wires on the battery side of the ammeter would probably be the power feed for the horn; you wouldn't want the ammeter kicking over when you press the button.
.
Joined: Jun 2018 Posts: 64 Threads: 16
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On my wiring diagram white & purple wire is from the ignition switch to ammeter, yellow & black wire is from starter to ammeter with a earth wire.
Joined: Jan 2018 Posts: 15 Threads: 2
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Nowadays with failing memory - but more wisdom, when dismantling anything I have to reassemble I take stage by stage digital photos. However I can forget where I left the camera or memory card.
Joined: Aug 2017 Posts: 861 Threads: 74
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Thank you for all the helpful replies, on and offline. I shall reconnect with confidence!
It could well be that I took photos Gary - I shall check my old phone ... if I can remember where I put it!
I'm wondering if there exists a wiring diagram with colours marked on? mine is a simple line drawing.
Peter.
Joined: Aug 2017 Posts: 861 Threads: 74
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Thank you Roly, that will make life much easier in the future. I shall print a copy to stash under the driver's seat.
The ammeter is back in and working correctly.
Peter.
