98sRgreat

Okay, so I bought new L.E.D rear brake lights, and third light as well... I got the third tail light from a different site then the rear lights . BAAADD choice, the rear lights were a breeze, true plug and play install. Not the same story for this "other" light. It did not come with a plug, just two bare wires, and no wiring diagram. Very disappointing, to top it off, I realized this fixture didn't even contain Cargo Lamps! Man was i pissed, bc none of this was in the discription. Instead of waiting to ship it back and order new ( im highly impatient ) i'd rather just mod this myself to make it work. I need help finding a wire diagram for a 98 chevy silverado third brake lamp. I know theres two white, one blue with a white stripe, and a solid black wire. Does anyone know where to find aftermarket plugs to retro fit stock ones? I found suitable L.E.D's to use for the cargo lamps off of V-leds.com, but one more complication lies, i need to find a socket to fit the fixture i got... Ive included detialed photos, so please ANY and ALL info is greatly appreciated.

98sRgreat

Okay, so I'm making rather great progress, and just about got this all wrapped up, just want to make sure on one thing before i go splicing into what little wire i have. I got a diagram from my local library and printed it out. It shows which wire connects to what, which is awesome. My question is though, which white wire goes to which one, because they both share a white wire in common. Does it not matter, my logic says that it's the white wire paired to it's closest color mate. As you can see in the pics below i have three black wires coming off my new fixtures, and one red, and two brown, I labeled the diagram with boxes of the color according to the wire i think i need to hook it to. If im correct awesome, just want to play it safe, ANY and all Advice would be greatly appreciated!

**Note** I got two side marker sockets from a local auto store ( about $8 total ) and just ordered my HID L.E.D white lights from V-LED's

Cody188

I got the same light as you. I have a colorado though. But the wires coming out of my cab are a normal blue, a skinny black and a skinny grey with black stripe. All I need to know is which ones positive and negative

ericnottelin

If you don't have a test lamp, GO GET ONE!!! they are pretty cheap and will tell you EXACTLY what wire does what.

I am a bit confused regarding the white wire question. Are you still referring to the third brake lamp?

brendon557

is there an update on this or anything? Im trying to do the same thing right now and cant figure it out

ericnottelin

Brendon, as you can tell, the above mentioned work was discussed. However, several people had questions to assist them further but no further detail was given. If you have a specific question, please ask it and we will do all we can do to help you out.

Just FYI, if you are having similar problems, I will ask you what your test meter is telling you and hopefully I can guide you from there. If you have questions about the meter, ask those too.

Hope I can be of help

Eric

brendon557

ok cool thanks. Im trying to avoid buying a meter becus im tight on money. But if i have to I will try. But my question is.

How do you do it I guess? Mine looks the exact same same wires and everything.

So which wires go where?

Hope you understand what im saying.
thanks

ericnottelin

Brendon, I do understand your question. There are four wires coming out of your wiring harness correct?

Ok, from looking at the wiring diagram, this is my guess.

Black (ground for entire circuit)

Blue w/ white stripe (brake lamp circuit)

White wires (cargo lamp circuit)

WARNING - this is a guess because the whole wiring diagram is not in the post by 98sRgreat.

A meter would be helpful because you could run a continuity test on the black wire to a body part to verify it IS ground (probably is). And you could then use the black wire as a base. Turn the meter to voltage and put the black lead to the black wire. When you put the red lead to any of the other wires there should be 0 volts (sometimes you get .1 volts but you shouldn't get 12 volts with the cargo lamps and brake lamps off). Now, have someone sit in the truck and press the brake lamps. Keeping the black lead on the black wire, probe the other wires with the red lead. When the meter reads 12 volts, you have the wire that activates the hot (red) side of your kit for the brake lamps. (NOTE: make sure the meter reads 12 volts positive and not negative. If the meter reads -12 volts, you have reverse polarity.). Have your helper pump the brake pedal to ensure that wire goes on and off as the the brakes are depressed and released.

Now, have your helper put on the cargo lamps. My guess is both the white wires will energize. One for each lamp. But use the meter the same way as above to verify.

Once you have verified what wires go where, you can now attach the three black wires (one from the led kit and one from each of the cargo lamps) to the black wire from the harness. The red wire from the led kit would go to the wire you verified with the meter, and the cargo lamps wire will go with the remaining wires.

So, you see why I am really adamant about getting a meter. You can get one for about $10 at Wal-Mart. You don't need anything fancy.

Let me know if you run into any snags.

Hope this helps, Eric

brendon557

I think im gonna call around to a few friends and see if one has a meter i can use. so im thinking I will end up doing it like this.

Since there is 4 wires coming off of the truck 2 white (power), 1 blue (power), and 1 black (ground).

and coming off the after market 3rd beak light I have six. 3 black (ground), 2 brown (power) and 1 red (power). If you look at his pictures up top they are the exact same thing I have.

So this is what I think im gonna do.

the 2 white off the truck are gonna go to the 2 brown on the outside of the LED light (see his picture)

the blue wire will go to the red wire in the middle.

So this leaves me with 1 black wire coming off the truck and 3 black wire coming off the light.

Can I just hook all these together or would that be bad?

Keep in mind I haven't tested any wires yet, this is just going off the top of my head.

And for anybody in the future reading this don't try this. At least not yet. If it works I will post if it does in a little bit. If it doesn't I will let you know to.
Assuming I try it.

What do you think?

thanks for helping me out btw eric

brendon557

ok so i did it : ).
ignore my last post though. This is how I did it.

the 2 brown wires coming off the break light go to blue wire. Because that is the cargo lamp wire. Take the 2 black wires from the same part the brown wires come off of and hook it to the black wire. Now your cargo lights should turn on and off with the switch inside the truck.

For the middle one. Take the red wire and hook it to the white wire that is giving off power. take the black wire and hook it up to the other white wire that is your ground wire. Now when you hit your breaks the LED part should light up.

So the power wires are the Blue one (cargo lamp) and a white one (break lights)
The ground wires are black and one of the white ones.

Yes there is 2 white wires. And one is for ground and one is for power. It is weird but it is working. So I am hoping I did it right. It looks like i did.

Hope this helps everyone in the future. : ).

thanks for the help eric