Dash lights were cycling all night until the batterys went dead

[Senodil]

Hello, my truck is a 2018 2500 Laramie 6.7 CCSB. I installed the 52 gallon titan tank this weekend (I DO NOT recommend doing it without a lift BTW, PITFA), and Monday I tried using alphaobd to program the new tank size. I did not change anything since I needed a security cable to write changes, which I ordered. Looking back, I am not sure of the order I shut down the truck, unplugged my MX+ bluetooth OBD reader and re-plugged my MM3 into the OBD port but wondering if this could have triggered the issue. This morning my battery's were completely dead (battery's were purchased 9/22 2X Interstate H7 94R AGM 850CCA's), and when I pushed my start button the cargo light illuminated on the dash then everything went off. Thought I accidently hit the cargo light exiting which stayed on and killed the battery's but after pulling up my security cameras I could see the speedometer and main screen powering up and shutting off continuously. I read through the multiple threads with people having dash lights staying on and killing the battery's (read about multiple things causing this BCM, Thermostat control box on passenger side by glovebox, wet connectors, bad wire going the transmission, etc), but curious if plugging and unplugging the OBD devices could have "triggered" this issue. I charged up the battery's today and drove the truck about 45 minutes and it shut down properly. Any help, thoughts or experience with this or a similar situation would be greatly appreciated. I love this truck but if this is the start of an ongoing issue I am going to trade it in and get something else since I travel hundreds of miles almost every weekend for work.....

 

[Daw14]

Start with the simple ,clean your terminals and grounds .

 

[Senodil]

Start with the simple ,clean your terminals and grounds .

I cleaned and use battery terminal protector in addition to the chemically treated pads. Thanks for the tought though

 

[WY-Dave]

A couple of times I had the same dash cycling. I had the phone using Torque Pro hooked up to the MX. We stopped at a store and my wife stayed in the truck. I took my phone that was used for Torque. When I got back in my wife said the dash had been cycling. The other time is I come back from shopping and putting stuff in the back seat(no key in ignition) I could hear the clicking and see the dash cycling.
I haven't test my theory out, but what I am thinking is that something like if everything is going with a good connection then instead of turning the AP on the phone off. The truck is still trying to connected to the phone and cycling off when it can't.

 

[Senodil]

A couple of times I had the same dash cycling. I had the phone using Torque Pro hooked up to the MX. We stopped at a store and my wife stayed in the truck. I took my phone that was used for Torque. When I got back in my wife said the dash had been cycling. The other time is I come back from shopping and putting stuff in the back seat(no key in ignition) I could hear the clicking and see the dash cycling.
I haven't test my theory out, but what I am thinking is that something like if everything is going with a good connection then instead of turning the AP on the phone off. The truck is still trying to connected to the phone and cycling off when it can't.

Thank you for sharing! I watched it all weekend while I was traveling and it did not happen one time, going to try and reprogram the DTE later today then see what happens.