Google H3 BCM and also Colorado Canyon BCM.

There are cloning services out there so you can find your own BCM. On a scale of 1-10 (10 most difficult), a physical BCM replacement is about a 2.

 

If I'm following you, does this describe the situation?
..
Do you have aftermarket rear LED light assemblies or are you using the OEM rear light assembly with filament bulbs?

Does the license plate lamp work?

Are any of the interior instrument panel lights, or any interior internally lit switches or buttons not lighting up?

Did your truck come from the factory with the trailer hitch and wiring, or was that added afterwards?

I'm asking these questions because these different lighting circuits are all related in the factory wiring. Some of the lighting circuits use the BCM for control, while others are powered by relays and fuses. Understanding the full set of symptoms might help isolate the problem to a specific power circuit, ground stud or BCM output.

For reference, here's a copy of the wiring diagrams for your truck: 2008 H3 Wiring Diagrams

 

Hi. So yes that was correct but now there are no brake lights at all. No turn signals in the back. The front work except the one left marker light.
all the lights were swapped to led 2 years ago.
no issues till now. I did swap the tail lights back to the original to see if there was any difference, but there was not.
all of the driving lights work as normal front and rear, with only the brake lights and turning signals that have failed.As well as the right side 12V and high fan setting are working intermittent.
its a 2008 alpha adventure/ lux.

thank you for trying to help. I am beyond frustrated at this point. The shops won’t even call me back anymore. Everything was working perfectly then the right turn and brake stopped then the others one at a time now total failure.
i feel like i got $50K yard ornament at this point
thank you again
Rick

 

Did you check both bulb filaments?

 

Yes i did. Even tried different bulbs just to be sure.

 

Did you test the socket terminals?

 

By "no brake/turn lamps in the rear" do you mean both left and right? If so, check fuse 20 and make sure its not blown.

Does the license plate lamp work? There is a known issues where the harness to the license plate lamp chafes and can short to ground where it routes through the rear bumper, which creates intermittent problems with the other lights. The license plate lamp is also on the same fuse as the right rear parking lamp (Fuse 49), but since that lamp is working the fuse shouldn't be the problem.

Did your truck come from the factory with the trailer hitch and wiring, or was that added afterwards? If this was added afterwards and they spliced into the tail lamp wiring instead of using the factory provided trailer wiring that is blunt cut in all H3 harnesses, there is potential to create unexpected problems in the lighting circuits and/or damage the BCM.

The rear right turn and brake lamp issue could be a problem in the aftermarket LED light housing you have installed, assuming whoever installed it followed the factory wiring diagram and didn't jumper off of other things. Power to the two filaments in the normal tail lamp bulb comes from two sources. The brake/turn lamp filament is powered directly from the BCM, where the parking light filament is controlled by a relay and has its own fuse. The right rear and left rear parking lamp have independent fuses after the relay. Within the BCM the schematic shows that left and right tail lamps are in the same logic group and share the same fuse with the LED turn indicator lamps in the instrument cluster. When you are experiencing your intermittent problem with the turn indicator, does the turn lamp in the cluster show the turn lamp is working, or is it dark? Do the brake lamp and turn lamp intermittent operation occur at the same time, or are they independent of each other?

The heater fan, marker light and accessory jack issues are almost certainly not related to the BCM and lighting, and are probably separate issues unrelated to each other. That means they should be investigated one by one. Just to confirm that, did you notice if these issues come and go independently, or when one isn't working, none of them are?

The aux connector not working could be a fuse - have you checked those? One of front aux ports is on the same fuse as the aux port in the back (Fuse 45) and the other is on its own fuse (Fuse 51).

The front left marker light is on the same power circuit as all the other parking/running lamps, and since all the other lamps work it is most likely a blown bulb. It could also be a broken wire in the wires connecting to the marker lamp socket.

The blower motor high speed operation is controlled by a relay attached to the bottom of the blower. If the relay is failed or missing then when you put the control to "high" the fan will stop working - is that what you are experiencing?

I will say that if the folks that rewired your harnesses didn't use the factory schematic to replicate the wiring and just jumpered stuff wherever then all bets are off on being able help you troubleshoot this. In that case you will need help from someone who knows how to read a schematic and use a voltmeter to troubleshoot electrical wiring problems.

 

 

My friend is bringing a multi meter over tomorrow to do that.
ill post the results.