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Center Top Stop Lite

I am going to assume that the AV is similar to the Silverado which I work on. If it is the same, the wire harness for the CHMSL is hot glued to the headliner. The wire follows down the LH "A" pillar to the junction box on the firewall next to the e-brake assembly. Please tell us why you need to tap in....do you have a new mod? We must know. :B:
 
Give a general idea of where you want to make the tap (under hood, under dash, under truck, by back seat, etc.) and I'll see what I can find.

If you have an '02, or an '03 with a trailer package, the simplest location might be the brake input signal on the trailer brake controller wiring harness that should have come with your truck.

What kind of load are you looking at? What will it do?

-- SS
 
Thanks for getting back to me.I would like to tap in at engine compartment and run back to new Center top stop lite on SNUG Top-Right now I am using the right turn/stop per SNUGTop instructions.AS your know this way makes the Stop lite flash when using right turn signal.
 
sjudson said:
Thanks for getting back to me.I would like to tap in at engine compartment and run back to new Center top stop lite on SNUG Top-Right now I am using the right turn/stop per SNUGTop instructions.AS your know this way makes the Stop lite flash when using right turn signal.
Click to expand...
OK. Looks like there's a few ways to do it.

The center high mounted stop light (CHMSL per GM terminology) is controlled by its own fuse and wiring. The simplest way to tap into this circuit would be to use a fuse tap (available at auto parts stores, it's a thin brass blade that slips in next to the fuse blade) and connect to the 10 amp CHMSL fuse in the under hood fuse block.

The next place you can get to it is the grey C1 connector that plugs into the bottom of the fuse block. To get to this you need to disconnect the negative terminal from the battery, and then remove some brackets and bolts so you can lift up and turn over the fuse block. The CHMSL circuit is a light blue wire in position C11. This pin is highligted in red in the following picture:

FuseBlock_C1.jpg

​
I'm sorry, the picture attached to this post is corrupted, the correct picture is attached to the next post, and is referenced correctly immediately above.

From here, the wire dissappears into a bundle, and enters the interior of the body. If you want to tap in under the hood, back at the fuse block is the place.

If you need more info on taking off the fuse block, and getting to the connectors underneath, look for the excellent post on the single wire all four headlights mod. That has the step by step instructions for working with the underhood fuse block.


There is one more alternative. I'm assuming you are currently tapping into the right turn/stop circuit of the trailer wiring. For trailers, these two functions are combined, which causes problems, as you have found. However, there are a total of four bulbs in the Av's tail lights, two on each side. All bulbs are low intensity tail lights, but they each also have a high intensity filament for stop and turn functions. On each side, one bulb is the turn signal, and the other bulb is the stop light. This is all a long explanation saying that the tail light wiring is already segregated into stop and turn functions.

Therefore, if you skip the trailer wiring, but instead tap into the stop light function at the tail lights, you will be able to find a dedicated stop function. Again, this will be a light blue wire. If you look under the right rear fender of the truck, you will see a junction block mounted on the wall of the fender, behind the rear tire. Looking at that, you should see the cable that runs from that junction block up to the right side tail lights. If you look in that bundle of wires, there is a light blue wire. Tapping into that wire should give you the signal you want: active only when the brakes are on.

Good luck, and if you need more details than that, let us know.

-- SS
 

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Sorry, looks like the original attachement is corrupted. Let's try this again.

-- SS
 

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This is off topic


At work one day I had access to a fellow coworkers truck. I also knew he was coming to get his toyota Tacoma in the early AM >:D

I parked his truck against a fence, to force him to reverse to leave. Popped out his taillight and stuck a wire into the reverse light socket. ran the wire under the drivers seat and hooked it up to a 120 dec. car horn >:D

It was all worth it!
 
Some more off topic...

During my sister's wedding reception, my new brother-in-law's brothers and cousins and I went out to the parking lot and rewired his car. When it came time for the newlyweds to leave, a cousin pulled the car up to the door for the new couple, making sure to use the parking brake to stop it.

The newlyweds got in the car, got ready to leave, and then the horn started honking. It took a few seconds for my brother-in-law to figure it out, but whenever he hit the brake, the horn would honk!

Sure was interesting as they drove off...
eyepop.gif


-- SS
 
Thanks ShapeShifter and everyone else,I think I will use the fuze block idea but it's nice to have other ways also.I have been in that area many times and that works best for me,will let you know how it goes.
Thanks Again,sjudson
As for rewireing other vechicles without the owners knowledge,when I was 11 I switched all the igntion wires around on my fathers friends truck.My father gave me a lesson why not to touch a mans truck (painful to sit down afterwards)
 
sjudson said:
Did the fuze block tap-Worked GREAT-Thanks again you gave me the RIGHT INFO
Click to expand...
Glad to help, happy it worked out.

Did you tap on top where the fuses are (easier), or underneath on the the connector (neater)?

-- SS
 
After reading this thread I thought maybe my brake light was flashing and I didn't know it. It was wired per the Snugtop instructions and it works fine. It is tied in on the Left hand side though. Thats where the wires come out under the carpeting. Maybe a later version?
 
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