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**VetteVet** · 08-21-2017, 01:59 PM

I did run across this thread cause I usually scan the forum for electrical forums at least once a day. I didn't look at this thread because I thought someone would have already answered it before now.

I don't have a cargo light in my truck and I haven't seen a wiring diagram, so I had to do some searching and I came up with these threads. Jim's is actually the first one listed

http://67-72chevytrucks.com/vboard/s...archid=5802902

There are some differences in the cargo light and the rest of the interior lights and so the wiring is slightly different. As I understand the operation of the light, the interior (dome) light has to be on in order for the cargo light to get it's ground.

Also it is switched on the ground (white wire side) and the power is wired directly from the dome light (orange wire). I still haven't confirmed that the switch is on the white wire or the orange wire. From what you are saying that you have 12 volts on the orange wire at the switch and at the light socket then it would have to be switched on the orange wire and you should not see 12 volts on the bulb socket with the switch in the off position.

Here's the dilemma, With it wired so the dome light has to be on and the orange wire hot all the way to the cargo light, the light housing would have to be insulated from the metal cab or it would be on all the time. What they did was to wire the ground and power wire directly to the bulb socket and not have the socket touching any ground except the housing.

The best option for me would be to ground the light housing to the cab and switch the orange wire to the light socket. This makes the cargo light independent of the other lights but would have to shut off to avoid draining the battery. Just like the other lights.

Iversaw you are correct about the voltage reading. The volt meter wouldn't read the resistance or voltage drop unless the ground path was connected and current was flowing through it. A good example is the resistance wire to the coil in the points ignitions.
If you read the voltage on the wire with it disconnected and the key on it will read 12 volts but with it connected it will read 8+ volts.

08-21-2017, 01:59 PM	#5
VetteVet Msgt USAF Ret Join Date: Jan 2005 Location: Kalamazoo, Michigan Posts: 8,703	Re: cargo light doesnt work I did run across this thread cause I usually scan the forum for electrical forums at least once a day. I didn't look at this thread because I thought someone would have already answered it before now. I don't have a cargo light in my truck and I haven't seen a wiring diagram, so I had to do some searching and I came up with these threads. Jim's is actually the first one listed http://67-72chevytrucks.com/vboard/s...archid=5802902 There are some differences in the cargo light and the rest of the interior lights and so the wiring is slightly different. As I understand the operation of the light, the interior (dome) light has to be on in order for the cargo light to get it's ground. Also it is switched on the ground (white wire side) and the power is wired directly from the dome light (orange wire). I still haven't confirmed that the switch is on the white wire or the orange wire. From what you are saying that you have 12 volts on the orange wire at the switch and at the light socket then it would have to be switched on the orange wire and you should not see 12 volts on the bulb socket with the switch in the off position. Here's the dilemma, With it wired so the dome light has to be on and the orange wire hot all the way to the cargo light, the light housing would have to be insulated from the metal cab or it would be on all the time. What they did was to wire the ground and power wire directly to the bulb socket and not have the socket touching any ground except the housing. The best option for me would be to ground the light housing to the cab and switch the orange wire to the light socket. This makes the cargo light independent of the other lights but would have to shut off to avoid draining the battery. Just like the other lights. Iversaw you are correct about the voltage reading. The volt meter wouldn't read the resistance or voltage drop unless the ground path was connected and current was flowing through it. A good example is the resistance wire to the coil in the points ignitions. If you read the voltage on the wire with it disconnected and the key on it will read 12 volts but with it connected it will read 8+ volts. __________________ VetteVet metallic green 67 stepside 74 corvette convertible 1965 Harley sportster 1995 Harley wide glide Growing old is hell, but it beats the alternative.