Ammeter gauge

Should you fit an Ammeter gauge what can it do?

The ammeter indicates how rapidly electrical energy is flowing into or out of the battery, and whether electrical equipment is consuming more or less electricity than is being
generated.

Instruments can warn of technical trouble in time to prevent serious damage and costly repairs. For that reason, it may save money to fit at
least some of the more useful instruments. When fitting a new gauge Ideally, they should be mounted in line with existing instruments.so as to not divert
the eyes very far from the road ahead.

Testing electrical circuits Individual circuits on the car can also be checked with the ammeter.

The main job of an ammeter is to show the rate of charge or discharge to or from the battery. But it can also give information about the rest of the circuits and components.
Checking the charging system If the charging system is working properly and the battery in reasonable condition, when the engine is running the ammeter should show a charge rate of between 20 and 30 amps (if the electrical equipment is not in use). After a few minutes the rate should drop and after several miles it should settle between 0 and 5 amps.

Testing electrical circuits Individual circuits. Note this is useful for items with loads that fluctuate such as wipers and indicators.  

When the engine is running at speed the ammeter should not show a discharge even when the head-lamps, wiper and heater motors are turned on. If it does, check the fan-belt tension. If this is correct, check the generator or voltage control unit. A continuous low rate of charge could be caused by a slipping generator belt so tighten this.

Switch on the ignition, but do not start the engine. Operate the flasher switch. Each side should register the same amount of discharge. If one shows more than the other, the bulb, cable connections or earth may be faulty. With the Windscreen wipers on and wet witch on the windscreen wipers. The ammeter reading should be steady, except for a slight increase as the blades change direction at the end of their stroke. If the needle fluctuates as the blades cross the screen, or if the discharge rate gradually increases, the wiper drive mechanism is faulty.