User`s guide

Permanent In-Vehicle Hardware Installation E
Agilent E6474A User’s Guide 217
• Connect it to a 12 volt power lead that is switched on and off
by the ignition switch.
Connecting the Ignition Sense Lead to the Fuse Block
Because each vehicle is different, the installer must determine
the best method for attaching the lead to the fuse block. We
recommend that you crimp a quick-disconnect terminal onto
the lead, then plug the terminal into the fuse block.
Connecting the Ignition Sense Lead to a Switched 12 Volt Lead
Locating the 12 Volt Power Leads
1 Remove the steering column panel or the lower dashboard
panel. (See Figure 76 on page 216.)
2 Locate the two 12 or 10 AWG wires under or near the
steering column.
3 Using a voltmeter, identify the lead that always measures 12
volts.
4 Using a voltmeter, identify the lead that measures 12 volts
when the ignition is switched on.
Connecting the Ignition Sense Lead to the Vehicle Wiring
1 Cut approx. 12” (30.4 cm) off of the ignition sense lead of the
cable assembly.
2 Crimp an inline fuse holder onto the 12” (30.4 m) lead.
3 Crimp the other side of the inline fuse holder onto the
ignition sense lead of the cable assembly.
4 Connect the free end of the 12” (30.4 cm) lead to the switched
12 volt lead using a wire tap.
NOTE
Direct Connect Hub: If you do not connect the Ignition Sense lead of the
power cable for the Direct Connect Hub, the unit can only be powered on
and off via its front panel switch.
The ignition sense wire color code is specified under “Main Power
Cable" on page 214.