Stu761

08 Equinox.....third light works but lower brake lights do not....
Fuses good ....changed bulbs.....changed brake switch....changed turn signal switch.........all other lights work.... tails lights which is the same bulb...
Don't no what to do next

oldchevy

Don't know about the Equinox but Chevy was having problems with the board that the bulbs plug into. The Trailblazer especially had many problems with these boards. Check to see if the voltage is getting to the board.

Stu761

Thanks I will look into that...its just weird that the tail lights work and the brake lights don't and its the same bulb

Stu761

Where is the board located

ruley73

Oldchevy was referring to the circuit boards in the tail lamp assemblies. These failed a lot on the older C/K trucks and vans. The Equinox doesn't use these so they are not a factor. I just wanted to confirm that the rear turn signals work fine. Is that correct?

Stu761

ruley73,

Yep turn signals work fine....The brake light bulb is for the tail lights too....and the tail lights work just not the brake lights

ruley73

So, I finally got a chance to look at the wiring diagrams. It makes sense that the turn signals and all the tailights work fine because the tail lights, turn signals and brake lights are all on separate circuits. Even though tail lights and brake lights use the same bulbs, each bulb has two filaments - one for the tail light and one for the brake light. The turn signal bulbs work the same way. Each bulb has two filaments - one for the tail light and one for the turn signal.

So, with all that said, I've narrowed it down to one of three things (assuming there are no wiring issues):

A) The Stop Lamp fuse is blown (#27 in the underhood fuse block, 15 Amp).
B) The wrong bulbs are installed - Make sure that 2057 bulbs are installed (1157 will also work). Any bulb number ending in with 6 should NOT be installed.
C) The Stop Lamp PCB Relay is bad. This a printed circuit board relay that is part of the fuse block and is not serviceable, so if it's bad the entire underhood fuse block needs to be replaced. There are four different part numbers. The engine your Equinox has (3.4L or 3.6L) and whether or not it has the towing package (option code V92 - look at sticker on glovebox door) determines which fuseblock you need:
20819327 - w/3.4L & V92
20819328 - w/3.4L EXCEPT V92
20819329 - w/3.6L & V92
20819330 - w/3.6L EXCEPT V92

The center mounted brake light is tapped into the brake light power source before it goes through the Stop Lamp fuse or the Stop Lamp relay and is fused separately (CHMSL/DM/LAMP - fuse #22 interior fuse panel, 15 Amps). This is why it still works fine. I've attached the wiring diagrams below for your viewing pleasure.

2007-2009_Equinox_Torrent-exterior-lights-circuit-1-of-2.pdf
2007-2009_Equinox_Torrent-exterior-lights-circuit-2-of-2.pdf

Stu761

Ruley73,

Thanks a lot I will check it out.....the bulbs I changed and they are the 2057 and the fuses are good ....so sounds like its the relay then.....now to figure out if its something I can do or do I take it somewhere.......

Thanks Again

ruley73

Replacing the underhood fuse block actually looks fairly easy. It definitely looks like something you could do yourself. I've attached the instructions below along with an enlarged picture. I'd try to remove it and reseat it to freshen up the connections before replacing it to see if that fixes your issue. A bad connection to the relay would be enough to prevent the brake lights from working.

2007-2009_Equinox_Torrent_underhood-electrical-center-or-junction-block-replacement.pdf

Stu761

ruley73,

Thanks you have been a big help......it looks like something I can do ....I will check the connection first.....
Thanks again