Ammeter problem?

[Graham Honnor]

I have just removed my ammeter to fix a loose glass and upon re-installing it I couldn't remember which
side the wires had come off from so I tried one way and then the other.
I now have no lights and no spark to the plugs.
If I had connected it the wrong way round initially, might I have damaged the lighting switch or something else please?
I'm about to start checking wiring etc. but any thoughts would be gratefully received.
I've checked the main fuse and that seems okay but will check it again.
The vehicle is a '37 Ruby with positive earth.
Many thanks for your time.
Graham.

[Ian McGowan]

Connecting the ammeter the wrong way round will do no damage, merely causing it to show a discharge when charging and a charge when discharging the battery. This excellent wiring diagram by John Cornforth should help you out of your current (no pun intended) predicament.

http://www.da7c.co.uk/
 look under "technical torque topics" and then under "electrics" and then "Ruby Wiring Diagram"

[Chris KC]

I suspect you've dislodged something else while removing/ replacing it Graham.
Mind you, I'm the last person I'd take advice from on electrics!

[bob46320]

Is the ammeter broken now ?? If current can't pass through the ammeter, then you won't get anything except the starter to work. You have 2 different circuits that are "Broken" Ignition and Lights, the first is via the ignition switch and the other is independant of the ignition and is controlled by the light switch (Allbeit its the same switch cluster on a Ruby).

[Graham Honnor]

Would it be safe to join the wires together and bypass the ammeter to test it please?

[David Stepney]

Would it be safe to join the wires together and bypass the ammeter to test it please?

Yes, Graham it would. The ammeter only measures the current passing through it, so wiring it out will make no difference to the circuit(s). If, once you have bypassed it, everything works, then the ammeter gone 'open circuit'.

[Graham Honnor]

Many thanks to all of you for your most helpful replies.
I had in fact killed the ammeter somehow by fixing the glass.
It has taken me all this time to find a replacement that I had kept from 
my 80" Land Rover days, and once I fitted that all electrics were once 
again restored.
I will now have to refrain from constantly tapping the glass on this "new"
ammeter otherwise I'll be back to square one.
Thanks again to you all.
Graham.