BCM reprogram for hyperflashing led's

[SS FORCE]

I'm working on converting every light on the truck to LED, just like my old 1997 however change in the years changes what needs to be done to correct some of the issues presented with LED's. On the 97 buying an led compatible flasher fixed hyperflash, on the 06, not so easy. I have read that clipping the 7 pin on the board of the flasher will stop hyperflash, I am here to tell you yes it does in fact work ONLY IF you are replacing the front lights with leds. Once you have the front and rear blinkers changed to LED you start to get random lights flashing that shouldn't be flashing such as your third brake light and your marker lights. Ask me how I know, got a mouth full from my dad doing the same to his soon to be fully led converted 05.

From what I have read GM has the BCM controlling flash on the back half of the later model trucks. My understanding is they did this so they could program the BCM to accept a standard or long bed setup with incandescent lights or change the programming on the BCM to accept leds on a flat bed configuration without dealing with the hyperflash issue. My thoughts are just find someone who can reprogram that for me and not deal with the trying to talk the stealership into it. Has anyone heard of this or know if I'm headed down the right path? I know there are load resistors but I hate to cut and splice wires I don't need to and feel this is a much cleaner solution. side note- I tried tying in a load resistor and it solved the hyperflash issue when the marker lights were off but once they kicked on there was no flash at all and current was fed back through the system illuminating my dash blinker indicator when the turn signal was off.

 

[THEFERMANATOR]

I thought the bcm control didnt start until mid year 07. Pretty sure there is an led flasher for the early 07 and older trucks.

 

[SS FORCE]

Thanks Ferm, I had read somewhere that bcm control on the newer years but based on the way our trucks were acting I thought maybe the 05-06 years were the same. My father purchased the led capatable flasher for his truck and it ended up not working out for him. Could have been faulty i guess, could also be the leds. I was hoping you would chime in as your the man that would know.

 

[THEFERMANATOR]

I'll check when I get home, but theres a thread somewhere here about it.

 

[Vito Longo]

2000 GMC SIERRA CLASSIC 3500 HD REG CAB 159.5" WB C5B
“TRIM LEVEL: REG. CAB 2WD
STYLE: CHASSIS AND CAB
F: ENG OPT - L65 DISPL(L) - 6.5T DURAMAX OHV 16V TURBO DIESEL - V8 FUEL SYS - DSL PROD IN - U.S.

I'm interested in bomb proofing factory design faults out of this welding rig and upgrading to leds all over also. I did a major scraping, prime and paint of the entire undercarriage. I uncovered a problem when i tested the break lights though. It seems the wires feeding the break lights were poorly routed under the frame rather than through it, so i chose to cut and reroute the wiring on both rear lights though the frame so as to protect them from damage and hide them so it looked tidy. The rear brake and reverse lights on the right side don't work. I cant remember but either the break light or the reverse light on that side is very dim, almost nonexistent, however on the left side the led lights were much brighter - the break light was a more robust red and the backup light was also bright but a cool white (almost blue huge). I originally thought the defect was due to me splicing them poorly but I was very careful. However after reading from a post in this forum that I may have neglected to remove paint at the frame ground coming from the light fixture. So far I'm not experiencing hyperflash but am expecting this problem to crop up. I'd rather not install resistors as they use energy, get hot, and take more time to install at every light. I did however with much searching find an led flash unit from some obscure web sight. I didn't look under the dash yet so I cant see the shape and pinouts of the the existing signal flasher. I'd sure like to get this over with and move onto other things as I thought the truck would be ready by spring and it's late May I kinda got over my head with all the changes I made but dont regret it too much because it sure is fun and I have a backup truck but this is my main rig.

 

[Will L.]

I used to own a truck equipment shop building cab chassis trucks, welding rigs being one type.

The frame is still exposed through holes for the ocassional wild grinder spark, etc. We took the entire rear harness from under the cab and reran it through 3/4" emt electrical conduit along side the frame to the drivers rear, then another conduit over to the passanger side. Depending on bed design a transition to steel (not aluminum) flexible conduit was used going up the frame to the light. It took some time to make the run, but is how it should be done for that type of service truck.

An added feature to the factory harness was always a carried ground wire to the rear- exposed grounding locations on a service truck always needed repairing.

As for bomb proof and switching to led- no. There is a reason all life critical lighting is done with pure tungsten filament lamps. Led is nice and cool- but still to new a technology to have the kinks worked out yet. You need to decide the trade off your willing to deal with. Power usage and brightness vs simplicity and longevity.