Simple question about earthing points in the front of a 73 Devon - is the earth tab on the back of the instruments an earthing point itself (because the back of instrument panel earths through contact with the body somehow) or does it need to be connected to a chassis earth?
It's isolated from the body via the plastic housing so should have an earth cable back to the earth cluster on the body.
If you're rewiring the dash panel take the opportunity to ensure the leads are long enough so you can pull the panel forward to rest on the top of the steering column and keep it working. Handy if you're testing lights or the fuel gauge.
