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Discussion Starter · #1 ·
If I am to understand correctly, the 2015 ram truck has PWM lighting system. I also come to understand that this is what causes a lighted hitch cover to blank when the right turn signal is on. Does anyone know how to build a PWM adapter or module to filter out everything but the brake light signal or how it could be wired/ Rewired to prevent it from blinking with the right turn signal? The only suggestion I have seen is to run a wire to the 3rd brake light which seems excessive. There should be an easier way without running a bunch extra wire from the cab back is I don't know of any 3rd brake light wire near the hitch, bumper or trail light area.
 

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Very interesting! Now I know why my Hitch blinks with right turn signal lol I thought I did something wrong :O So what does a PWM system do ?
 

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Discussion Starter · #3 · (Edited)
I found out that Dodge 2015's have a 3rd brake light only wire near the spare tire that is just looped and taped up against the wire harness. This wire is there to wire for trucks that have truck caps with the 3rd brake light. I don't know when they started that and if the Rams going back to 2013 or 2012 or earlier have the same wire but you have to rewire your lighted truck hitch cover to plug into that wire to prevent it from blinking with the right turn signal.

The bully ones made by pilot that have the RAM logo on the cover that lights up ( model CR-007D) cannot be plugged in to the 4 pin connector without having them blink with a right turn signal. The one that is just a square light (model CR-007A) comes with a PWM converter wired into it that is supposed to cancel out the blink signal. I even tried combining the left and right wires on a custom extension cable thiking that even though the right blinks, it would still get a steady continuous signal from the left but it's still blinked because of the pwm system. An extension cable is needed on the CR-007D because the provided cable is too short for RAM trucks even though this model is specifially designed for RAM. I read that you can go the dealership and have them turn PWM off. I'm not sure what they would charge for that or if you can do-it-yourself with an OBD II programming device but PWM has to be turned off in the bcm in order to use the OEM For pin flat trailer hitch connector near your license plate and prevent your hitch cover from blinking with the turn signal apparently from the research I have found .... finally. I must have been researching or searching the wrong info for days. I never thought I would see the day when vehicle rates were electronically controlled.
 

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I found out that Dodge 2015's have a 3rd brake light only wire near the spare tire that is just looped and taped up against the wire harness. This wire is there to wire for trucks that have truck caps with the 3rd brake light. I don't know when they started that and if the Rams going back to 2013 or 2012 or earlier have the same wire but you have to rewire your lighted truck hitch cover to plug into that wire to prevent it from blinking with the right turn signal.

The bully ones made by pilot that have the RAM logo on the cover that lights up ( model CR-007D) cannot be plugged in to the 4 pin connector without having them blink with a right turn signal. The one that is just a square light (model CR-007A) comes with a PWM converter wired into it that is supposed to cancel out the blink signal. I even tried combining the left and right wires on a custom extension cable thiking that even though the right blinks, it would still get a steady continuous signal from the left but it's still blinked because of the pwm system. An extension cable is needed on the CR-007D because the provided cable is too short for RAM trucks even though this model is specifially designed for RAM. I read that you can go the dealership and have them turn PWM off. I'm not sure what they would charge for that or if you can do-it-yourself with an OBD II programming device but PWM has to be turned off in the bcm in order to use the OEM For pin flat trailer hitch connector near your license plate and prevent your hitch cover from blinking with the turn signal apparently from the research I have found .... finally. I must have been researching or searching the wrong info for days. I never thought I would see the day when vehicle rates were electronically controlled.

Thank you for the education lol. I have the Bully w/RAM head CR007D ,and a 2015 RAM.. I will look for that wire ! I did add a T connection with 5 pin plug, so I now have a 4,5 and 7 pin.. But when I tested my RAM head and saw the Right sigle flash with the head I thought I did something wrong lol.. GREAT info... So what does the PWM do or what is it used for ??? Inquiring minds want to know :) Could not find anything on google yet ! Thanks
 

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Discussion Starter · #5 · (Edited)
Radio, PWM stands for Pulse Width Modulation. Even though the taillight bulbs on my 2015 still have to filaments, using electronic pulse width modulation could be used to control one bulb filament for breaking in blinking. I read somewhere someone mentioned that taillights on ram trucks have 7 wires going to the tail light bulb socket. Maybe some Chrysler lighting engineer could explain all this mess, LOL Now with the trucks in 2018 coming out with led lights, they have been turning PWM off at the factory but still including it in the bcm in case somebody wanted to downgrade back to incandescent lights. I imagine led lighting is also electronically controlled by some other electronic module that controls braking and blinking but I'm not sure how that works. You don't need PWM for incandescent lights but that's what they started implementing it for. Apparently at keeps bulbs from dimming during start and other voltage fluctuations and makes incandescent bulbs last twice as long. In Other words, instead of your taillights bringing out in 4-5 years maybe they only burn out in 8 to 10 years after you've sold your vehicle to the 2nd owner. I'm not really sure if its the PWM system that makes these blank with a right turn signal or if it's just the way the 4 pin flat connectors wired. I have seen a few different ways that 4 pin connectors can be wired. Used to be that a 4 pin connector would have ground break and left and right wire were control blinking which was controlled by a relay under your dash But from what I've read so far is seems that ram truck 4 pin connectors may be wired differently in control by the pwm.
 

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Ramma again thank you for the education. Since we have the same year RAM's all info fits my truck as well :)
 

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Discussion Starter · #7 ·
I used the third break light wire beside the spare tire that Chrysler put there for truck caps. It works. I just strapped it up behind the bumper. The wire you are looking for is white with a brown stripe. It is looped around and trapped up against the wire harness.
 
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