Joe,
The vc light is fixed to type 10 light:
[LIGHTS]
//Types: 1=beacon, 2=strobe, 3=navigation, 4=cockpit
light.0 = 3, -4.65, -16.86, 3.34, fx_navred85
light.1 = 3, -4.69, 16.80, 3.34, fx_navgre85
light.2 = 3, -20.9, 0.0, 1.3, fx_navwhi85
light.3 = 1, -18.4, 0.0, 6.25, fx_beacon85
light.4 = 10, -4.27, 0.0, 2.8, fx_vclightc185
light.5 = 10, -7.7, 0.0, 2.5, fx_vclightc1852
To turn it on (I couldn't find a panel light switch) I used the "L" key and then turned off the lights I didn't need. The vc light is red in this aircraft btw. I changed the vc light type to type 4, then you can use shift/ L combination to turn on the vc light.