ransley wrote:

What should the current draw be with a car parked, for the night, not
running, Volvo v40 with factory alarm but never activated. How do you
check this. In the morning my battery is low. Can I use a 120v digital
clamp on amp meter.

You should expect a standby current of perhaps .1-.2A at most, composed
of the ECM, radio, alarm and any feature module standby demands.

A clamp on amp meter will only work if it is the AC/DC hall effect type.
Even then, the expected current draw is so low that a clamp meter
wouldn't work well. You will generally need to disconnect a battery lead
and connect the meter in series using the appropriate connections for
it's DC Amp range.

Something as simple as a failed switch on a trunk or hood light keeping
it on will greatly increase the standby current. If the standby current
looks reasonable then the suspects are the battery and the alternator.
Other more unlikely suspects would be stuff like air suspension
compressors running periodically due to a leak, or a power radio antenna
continuing to run after it's down due to a bad limit switch. I don't
know what a Volvo v40 has so no idea if any of those are applicable.