The BSA A7-A10 Forum

Technical => Lucas, Electrical, Ignition => Topic started by: A7SS-rph on 22.05. 2020 20:06

Title: Ammeter mount
Post by: A7SS-rph on 22.05. 2020 20:06
The ammeter on my A7 does not have a mounting bracket and to stop it coming lose I put a tie wrap round the back.

I have seen a rubber ring listed. Is this to go under the bezel or on the back to locate it ?

Title: Re: Ammeter mount
Post by: Speedy on 23.05. 2020 18:26
As far as I can remember the ammeter is secured with a metal bracket which is held in place with the the 2 terminal studs , you might need to use rubber grommets on the terminals.
Or use 2 L shaped brackets on the terminal screws.  I think the Miller Ammeter used a large  C clip.
I had an old M21 and the ammeter on that kept jumping out of its headlight hole ,and when it did so all of the lights  would go out as the terminals shorted out on the headlight shell.  That was a circling that held it in place ,,but it kept falling off.
Title: Re: Ammeter mount
Post by: Swarfcut on 23.05. 2020 22:52
   Some ammeters have tangs (metal) or fingers (plastic mouldings) in the body, just under the bezel. The rubber ring goes under the bezel, and the ammeter pushes into the mounting hole. The tangs spring out to hold it in place.
     Rubber ring acts as a seal and keeps the tangs pressing against the back of the mounting panel. Sometimes the mounting hole has cut outs, matching the tangs. The tangs pass through the cut outs, then rotating the ammeter slightly locks it in place.

 A design using a metal bridge will have separate mounting points, this is the usual style for larger instruments, typically used on car dashboards. The terminals need to be kept well away from any metallic mounting.

Title: Re: Ammeter mount
Post by: A7SS-rph on 24.05. 2020 09:15
There are no mounts for the metal bridge.
Sounds like my only option is to look at the tang idea.

Thanks for the replies.
Title: Re: Ammeter mount
Post by: Greybeard on 24.05. 2020 10:01
You could maybe glue the ammeter in with silicone