Panasonic KX-TD816 Installation Manual page 115

3.
If two units are connected with the DC IN/OUT or a Battery Adaptor (KX-A46) is
connected to the unit, insert the 4-pin connectors to the jacks as shown below.
Also connect the ground terminal of the unit to the minus (-) terminal of a car battery using
an earth wire.
Note
Please make sure that the unused terminal* does not touch the car battery terminals.
General Installation
To another
KX-TD194 or
KX-A46
(See "SLT Message Waiting Lamp Adaptor Unit"
for a connection example.)
DC IN/OUT
2.4 Installation of Optional Cards and Unit
Car battery
Red
+ -
KX-A46
Yellow
Side View
unused
terminal*
115