spk93924
Junior Member
I have factory upfitter switches in my 2015 3500 6.7 that have never been used. I installed a lightbar and wanted to use Aux1 for switching. Before connecting anything, I noticed that when I press any one of the 5 buttons on the dash, the LED's for every button light-up. Also, there is no relay activity under the hood when buttons are pressed.
I've checked all fuses, relays, etc., and did come to find that the switch side of the relay is only getting about 9.6 volts. When I jump it w/12v's, it works fine. I swapped a switch panel from another truck without any change and inspected the bottom of the TIPM for any corrosion, etc. and found none.
The dealer has been useless in diagnosing (no suprise), and a specialty shop spent a couple hours on it and suggested perhaps a BCM issue, although he had no diagnostic tools to help him other than schematics to reference.
There have been two other very intermittent gremlins. 1) twice, the trucks electrical system failed to shut down after running for a couple hours. Even after shutdown and walking away with the key fob, dash lights stayed on and radio played and lights continued, even in the ignition "off" mode.
After 45 minutes, I disonnected the batteries for 15 mins to ultimately corrected the problem. 2) My HVAC system does not get completely hot. I have flushed the heater core (wasn't dirty at all) and confirmed 180 degrees on both sides of the core. I did have a local shop run a reset with their Aultel computer and it immediately blew smokin' hot for a couple days. Since then, back to luke warm every day.
I have tried the overnight battery disconnect and body terminal ground in hopes to reset BCM et. al. So far, no joy...
Anybody???
I've checked all fuses, relays, etc., and did come to find that the switch side of the relay is only getting about 9.6 volts. When I jump it w/12v's, it works fine. I swapped a switch panel from another truck without any change and inspected the bottom of the TIPM for any corrosion, etc. and found none.
The dealer has been useless in diagnosing (no suprise), and a specialty shop spent a couple hours on it and suggested perhaps a BCM issue, although he had no diagnostic tools to help him other than schematics to reference.
There have been two other very intermittent gremlins. 1) twice, the trucks electrical system failed to shut down after running for a couple hours. Even after shutdown and walking away with the key fob, dash lights stayed on and radio played and lights continued, even in the ignition "off" mode.
After 45 minutes, I disonnected the batteries for 15 mins to ultimately corrected the problem. 2) My HVAC system does not get completely hot. I have flushed the heater core (wasn't dirty at all) and confirmed 180 degrees on both sides of the core. I did have a local shop run a reset with their Aultel computer and it immediately blew smokin' hot for a couple days. Since then, back to luke warm every day.
I have tried the overnight battery disconnect and body terminal ground in hopes to reset BCM et. al. So far, no joy...
Anybody???
