<DIV>I need to know what color feeds power to the third brake light! </DIV>
<DIV>This is on my 04.5 D/A.</DIV>
<DIV> </DIV>
<DIV>I have four choices of color </DIV>
<DIV>1.black</DIV>
<DIV>2. blue with white stripe</DIV>
<DIV>3. light blue</DIV>
<DIV>4. orange</DIV>
<DIV> </DIV>
<DIV>I'm trying to wire a "brake light pulser" which is to "...pulse the center mount brake lamp when you apply your brakes."</DIV>
<DIV> </DIV>
<DIV>check out www. webelectricproducts.com if you want to learn more!!</DIV>
<DIV> </DIV>
<DIV>Thanks</DIV>

Take your third tailight apart and take a looksie at the wires.

Go with the light blue. Meter it with the brake pedal on, then
take the CHMSL fuse out, and meter it again with the brake pedal on to
make sure.



Dennis

Where are these 4 wires you speak of?


I agree with baimpala it is likely the light blue but depending on where you are tapping into the wire it might not function correctly.

FWIW - I know the Lt. Blue is the wire not used on the trailer harness
and it is designated as the CHMSL (wire is just folded back and taped
up on the harness).

Hi guys;


the four wires that I was talking about are at the third brake light it self!


What the instuctions say to do (for adding this brake pluse thing) is to cut the power wire to the brake light and splice one side of the pluse unit to the power that comes from the brake pedaland the other side of the pluse unit goes to the light with the third wire(on the unit) going to ground (which should be the black wire?)


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GMC or Chevrolet?

You must be overlooking the white wire at the stop lamp switch. It should be the wire closest to you. That is the correct wire at the brake switch. However, that will flash all of your brake lights not just your high mount stop lamp. You will have to tap in after the fuse panel to have it flash just the high mount stop lamp. I will need to know GMC or chevrolet to provide further information.

MP----


Chevy 3500

You are going to have to go to the back of the fuse panel on the driver side of the dash. Test with a test light. There will be at least 2 lt. blue wires there. There are two that will test +12v when the brakes are pushed and no voltage when the brakes are not pushed.


You want to find the one that has power when the brakes are pushed but looses power when the brakes are pushed and you pull the 10amp CHMSL fuse.

That is the wire you want to cut. That wire goes to your high mount stop lamp and to the trailer wiring plug. It does not control the left and right brake lights.





If you want all three lights to flash (high mount, left and right) then cut the white wire at the brake light switch.



Good luck!

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Thanks M P


I'm off with my test light in hand!!


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The proper tool for the job would be a Digital Multi Meter. You should be ok behind the fuse box with a test light but there is always a chance you will probe something you shouldn't causing computer failure or worse.

Hey Max, what do you do for a living, you sure have a lot of knowledge with these trucks and other things and you sure have posted on this web site alot http://www.dieselplace.com/forum/smileys/smiley1.gif

I wear quite a few hats. I deal a lot with Automotive Electical.

update!!





All is right in Fremont Nebraska or at least at my place. LOL


My brake pluser works .


thanks to M P for your time and effort!!

I think if you splice it there your trailer brake lights will also pulse. http://www.dieselplace.com/forum/smileys/smiley5.gif