use volt meter instead and reroute Alt to Starter
Are you aware the amp meter was deleted and replaced with a volt meter starting in/around 1988 (albeit by then the universal diesels)? Also, due to possible fire hazards, and strongly recommended by Catalina and the panel manufacturer, the alternator output was re-routed directly to the starter post (the orange wire) instead of taking the 30 foot route to the cockpit panel and then just disconnected at the panel. Lastly, an Amp meter can actually show less information than a volt meter, and by being able to be wired in parallel, eliminates the voltage drop/loss to the alternator output which would otherwise benefit the batteries. Below is the link to the panel manufacture where you can also buy the volt meter (or amp meter if you choose to stay that route -- but do read their 'upgrade information' before you decide not to switch to a voltmeter):
