Blind spot monitor stopped working / Rambox problems also [SOLVED]

[ds28]

Update: I am going to edit this first post to say the Rambox and the Blind Spot Monitor issues are related on my 2020 Bighorn Ram. They were both caused by corroded wire connections. I live in PA and snow and rain kick off the tires into this area with the rear harnesses. Note, these are both on the drivers side. The symptoms were the Rambox would pop open randomly, and then eventually I could not even open it without the key, but it would still pop open when it felt like it. The Blind Spot monitor system displayed an error when I would start the truck.
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It used to be intermittent but now I get the message that the Blind Spot detection is not working every time I start.

The left taillight harness is suspect. On pins 7 and 9 where I get 14 volts on the right tail light, I only get 12.9v on pin 9 and 7.9v on pin 7 on the left side.

I guess I will have to trace backwards from that wire harness and see where the loss in voltage is coming from.

Has anyone dealt with this and know where all I can easily access wiring that heads back to the left taillight ?

 

[ds28]

and my drivers side Rambox pops open randomly still. I usually disconnect the wire so I have to use the key to get in. Maybe related as I’m seeing water/corrosion is common here. It’s a 2020 Ram.

 

[ds28]

Here is the connector to the drivers ram box, I am guessing this is part of the circuit that goes to the taillight, causing loss in voltage due to corruption.

 

[ds28]

I reported both the Rambox and Blind Spot detection issues to the dealership while under warranty, but they were never able to find anything, and now Im at 81000.

 

[ds28]

posting this here to keep all related info in the same thread.

TSB23-012-21

NOTE: This bulletin applies to vehicles built on or after August 01, 2020 (MDH 0801XX) and on or before November 19, 2020 (MDH 1119XX) equipped with the Rambox Cargo Management System (Sales Code XB9).

SUBJECT: Driver Side Rambox Opens By Itself Unprompted

OVERVIEW: This bulletin involves removing the driver side Rambox and replacing the Rambox door lock actuator wiring harness with a jumper wiring harness.

SYMPTOM/CONDITION: The customer may comment on one or more of the following:

• Every time the vehicle is unlocked the driver side Rambox opens.
• Driver side Rambox opens for no reason. This can happen while the vehicle is sitting over night, or if the vehicle is left unlocked.

 

[ds28]

Well I am going to get a few new harnesses and hope this works. Some of the wires are so bad they are not even connected anymore. I am only going back to the main wire bus even though you can see there is corrosion coming off that pig tail too.
Parts I am buying: 68488850AB , 68365711AB

 

[ds28]

after replacing the 2 harnesses I now have the Blind Spot Monitoring system and Rambox working as they should for the first time in several years.