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Roof lights won't turn off

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SpotonJ

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Roof running lights (all the amber ones) won't turn off even when the truck is off.
All other lights are off.
I usually keep the lights set on "auto", but the problem persists even in "off" position.

I spoke with the dealership and on they're instructions I unplugged the grounds on both batteries and let it sit like that for 30 minutes.
As soon as I hooked the second battery's ground the roof lights turned on.

I called another shop and they suggested I disconnect both positive and negative battery terminals on both batteries for a few hours. I did.
Again, as soon as I hooked up the second battery's ground the roof lights turned on.

Any suggestions?
 
Are you saying they stay on 24/7 when you shutdown and walk away from the truck or just won't shut off while the truck is running?



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MtnRider said:
Are you saying they stay on 24/7 when you shutdown and walk away from the truck or just won't shut off while the truck is running?



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24/7.
They won't turn off at all.
I currently have the grounds unhooked from both batteries to keep them turned off.
They were on when I went out to the garage this morning. They must have been on all night.
 
SpotonJ said:
24/7.
They won't turn off at all.
I currently have the grounds unhooked from both batteries to keep them turned off.
They were on when I went out to the garage this morning. They must have been on all night.
Click to expand...
Did this all of a sudden start happening? Is there always 12v on the running lights pin on the 7-way trailer connector also?
F022DE9F-3AC3-4B80-8957-BF96693C45EF.jpeg
 
Check for corrosion in trailer plug and remember when checking for power at the tail pin it will be bottom right as the 7pin is upside down on these trucks
 
Jimmy07 said:
Ahhh, you’re the bumper fire truck…I’d say the running light circuit fried the trailer running lights relay control on the fuse box PCB, and the relay is stuck on 87, constantly feeding the cab lights
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If I disconnect the trailer plug (either unplug it further up at a harness or cut and cap the wires) until the new one arrives for the repair, will that take care of it?
 
SpotonJ said:
If I disconnect the trailer plug (either unplug it further up at a harness or cut and cap the wires) until the new one arrives for the repair, will that take care of it?
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Pull fuse F29 first, and note behavior of the cab lights. Pulling fuse F79 will kill the cab lights.
Either way, there is an issue with the trailer park lamp relay on the fuse box being stuck with 87 closed. It could also be the Trailer park lamp relay circuit on the BCM (which completes ground to the relay coil when the park lights are switched on) is faulty, constantly sending the signal to the relay coil.
 
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Jimmy07 said:
Pull fuse F29 first, and note behavior of the cab lights. Pulling fuse F79 will kill the cab lights.
Either way, there is an issue with the trailer park lamp relay on the fuse box being stuck with 87 closed. It could also be the Trailer park lamp relay circuit on the BCM (which completes ground to the relay coil when the park lights are switched on) is faulty, constantly sending the signal to the relay coil.
Click to expand...

If it was the BCM, are those resettable like the solid state TIPM or is it AFU?
 
I am having the same problem with my top cab light on. When truck is turned off as well. 2021 ram 5500 also when the trailer is plugged in there is about five of my bullet lights in the little three-quarter inch LEDs that are on the dim.
 
Nabes68 said:
I am having the same problem with my top cab light on. When truck is turned off as well. 2021 ram 5500 also when the trailer is plugged in there is about five of my bullet lights in the little three-quarter inch LEDs that are on the dim.
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Clean the trailer plug its back feeding the system at the rear 7 pin plug. I had it happen to my 19 just cleaned up the corrosion and regreased it with die electric grease no more issues
 
I separated the plug and zero corrosion. only thing I can think of is removing the wires from the back of the plugs and checking. it is wore when wet so i know its corrosion just not sure where.
 
Nabes68 said:
I am having the same problem with my top cab light on. When truck is turned off as well. 2021 ram 5500 also when the trailer is plugged in there is about five of my bullet lights in the little three-quarter inch LEDs that are on the dim.
Click to expand...
I pulled f30 and they all shut off. F29 and f79 didn’t change the outcome. The light flickered but that’s it.
 
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