Plug In Electrical System Tester Pix
 

Picked this up at local Wal Mart, under $20, good for anything with a cigar lighter.

Pix show my voltages at:

key on, not running (gets up to 14.04 at 50 mph)

Idle, nothing on

Idle, AC on high, light on high beam, flashers on, brake depressed, wiper on, radio on

Handy because it can move to multiple vehicles, boats, etc.

You only need it once maybe twice in the life of the vehicle for the alternator.

Nothing more.

Very true, and I have an assortment of meters. But this is handy for the four I have at home and the dozen at the office, plus the dozen boats (not all have lighter plugs, but most do).

My Mercedes believes that full charge is 13.35 volts, the factory sets them that way, so the batteries never last as long as they should, common problem with W124 series. Maybe I can find a variation of the regulator/brush assembly.

Main reason I tossed it out was to show people the voltage ranges. We can't even get owners to download the RAVE, so why would expect them to get permission from she-who-must-be-obeyed for more tools?