Thread: Ameter and Alternator

Gentlemen
I have often read that it is unwise to run the current from a modern Alternator through the Ammeter that was fitted to Series 1 Land Rovers. I can fully understand the issues with running a 40 plus Amp current though an old style 10 amp Ammeter, as the resulting smoke and melted wiring harness could seriously damage your mood.

However, I have purchased a 60 amp Ammeter, and plan to use that in my Series 1 which is fitted with a 40 Amp Alternator. Vinwires made the harness for me to take an alternator, but just wanted to check with those with greater knowledge of such things, if I am OK to use the 60 amp Ammeter with the 40 amp alternator?

many thanks in advance
Jeff in Perth

Jeff, have you asked the question of the supplier of the ammeter? Or an auto elec? Alternators don't produce "smooth" DC: it's a bit notchy and cheap multimeters don't like it. Ask whether the ammeter needs, or incorporates a shunt. This component, in series with the alternator and the battery, handles the bulk of the current, and the ammeter is connected across its terminals (in parallel). The shunt and the ammeter have to be matched, eg 75 or 200 ohms. It's the same deal with stand-alone solar systems: the battery charge controller uses an external shunt to measure the current coming in from the PV panels on the roof or a back-up generator, or both.
Trusting this helps,
Rob S