Trailer RT/ Stop circuit. Fuses F81 and F53 good

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MMorgan834

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I have followed a few threads looking for the answer but the F81 fuse seems to fix everyone’s problem. My fuse is good and there is no power going to the fuse. Where do I go from here? Thanks for any help.
Mike

2014 1500
 

ramrocker

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I think the BCM energizes the TT Right /Stop relay coil which is buried inside the fuse box on a circuit board.
So you'd think if the fuse F81 isn't getting +12V, then the relay isn't being energized or has gone bad.

Clip from Mpgrimm2's My 2013+ Shared Schematics and other OEM Info
2014 1500 Trailer Tow -1.jpg
https://www.ramforum.com/threads/my-2013-shared-schematics-and-other-oem-info.86768/
2014 Ram 1500 TA Schematics (full set, no connector sheets) - added 4-22-17
Chassis > Trailer-Tow-System
Power Distribution > Fuses-Relays Misc. 5.7
 

crash68

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Have you pulled the plug out of the back of the 7 pin? After that your going to need to check for power at the C7 pin 30 which is on the underside of the Power Distribution Module (fuse block). Also check the #16 pin on the on-line body connector which is under the truck behind the driver's front wheel.
 
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MMorgan834

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I will dive into this further tomorrow. Thank you guys for some more information to work with!
 
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MMorgan834

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I didn’t get very far. I guess I don’t understand what you’re telling me. If the fuse block F81 has no power on the load side or the source side, can I go any further? I took the PCM (fuses and relays board) off but I don’t see me doing any good trying to crack it open. Where is the BCM where I can test for voltage at point 22 C5/E?

Update. I do have 12 volts steady at C7 pin 33 which, as I understand, powers the relay. Or am I going the wrong way. It seems to be an issue inside the circuit board. I may be whipped on this trouble.
 
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crash68

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Update. I do have 12 volts steady at C7 pin 33 which, as I understand, powers the relay. Or am I going the wrong way. It seems to be an issue inside the circuit board. I may be whipped on this trouble.

If you have voltage at the C7 pin 33, that is feeding the relay. The way the diagram is drawn, it shows the fuse after the relay, check for power at the fuse. If it's there check C7 pin 30. Then pull the plug from the back of the 7 pin and check there, if nothing pull the body connector that by the driver wheel and check for power coming out of that, it should be a light green color
The BCM is under the dash on the driver's side. You can find those wires on the bottom of the fuse box also.
 
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ramrocker

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Yes the signal goes from the BCM to the relays, then the fuses, then back to the 7-pin.
If you haven't, swap the left turn light fuse with the right fuse to make sure don't have an open fuse.
I figure you've already tested them with a DMM ohmmeter.
I guess the hardest part is getting a DMM on the turn signal voltages from the BCM to the PDC/fuse box while the connectors are in place.

If the relay inside the PDC has gone bad I expect it's replacement.
I could, but wouldn't want to open one if they're similar to the old TIPMs.
Like:
 
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MMorgan834

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Thanks again. I believe that the relay has gone bad in the PDC. I will be on the lookout for a good price replacement. Until then, my trailer won’t have a right turn signal. It is in the dealership for some recall stuff today. They wanted $186 to diagnose. Screw that.
 
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