When you use a multimeter to measure electricity, you can measure amperes, volts, or ohms.

The usual thing that is measured is volts. For that the meter leads are connected across the battery or the load.

Check your charging system with the multimeter set to measure DC volts. Connect the meter across the battery with the engine running. It should read at min 13.5 volts, better is 14.0 to 14.5 volts. If it is close to or below 12 volts, the charging system is at fault.

Check the same with the key off. You should get 12 volts or a little more. Less means the battery is not charged and may not be able to hold a charge.

The Volvo voltmeter measure volts, not amps. Measuring amps is a bigger deal. The meter must be in series with the load. One may would be to connect the ammeter to the battery negative post with the cable removed. The other meter lead connects to the negative cable. Battery - meter- cable, like that.

Do not try that, it might be that the amp load would be beyond the capacity of your meter. Even thought most meters have a fuse for protection, it is a PITA to figure out what size fuse, get one, and install it, and hope. BTDT

On your alternator there should be three connections. A fat red with that goes to the battery, maybe to the starter, which carries the charging current.

A blue or black wire from the alternator frame to the block.

A red wire connected to an insulated spade lug on the alternator. When that wire is grounded, as it is when the alternator is not spinning, the dash warning lights will come on. When the engine starts running, that wire carries a small voltage that comes through the warning lights. That voltage gets the alternator started in charging. But the ground gets lost so the lights go out.

BUT - if that wire is grounded some other place, as with compromised insulation, the warning lights will come on and the alternator will not charge.

Also, if the alternator output voltage drops below the battery voltage, the batt. light will come on. How bright depends on how large is the difference between the two voltages.

You may have just a loose wire or weak connection, or you may have a failing diode in the alternator. Check the cheap stuff first, especially the brushes.

Good Luck,

Bob

:>)












To measure amps one must have