DesertMiner

What type of fuse does the inverter manufacture recommend? That’s usually a good place to start.

👍

Have you verified that all of your “charging” sources can be adjusted to the needed BB lithium settings? Some reworking of the battery interconnect cables will probably be needed going from 6volt in series/parallel to 12 volt in parallel. Will you be able to mount the BB’s in a area that you can control the low/high extreme temps?

(BB’s are a bit discounted for “Black Friday” and “Cyber Monday” on their website.)

I use the switches for safety and protection of my circuits and devices. 
I like these...

https://www.bluesea.com/products/6007/m-Series_Mini_Selector_Battery_Switch_-_Red

https://www.bluesea.com/products/9003e/e-Series_On_Off_Battery_Switch

https://www.bluesea.com/products/3000/HD-Series_Heavy_Duty_On-Off_Battery_Switch

Did I read correctly.... no disconnect switch between the batteries and the inverter?  

Did you try it with the truck running or just the key in the “on” position?

Is the 265 wheel base ok for your needs?

Might be a good time to continue your lug checking... inverter , batteries, and so on. 

You might check to see if you may have any other  remnants of a “Qualcomm” install. Lots of times when a “Qualcomm” is removed they just cut the wires and remove the pieces. Next time you have a minute remove the trim pieces that keep the floor mat down on the passengers side door opening. Lots of times that’s where they run the wires. Been stories  told of folks fixing the “electrical gremlins” In the rigs by checking those wires. 

I thought you mentioned you had an inverter, does it just power the fridge?

Any chance you could add “2021” in the title?  TIA

What work was done at the shop?  (Assuming none of these issues existed prior to going to the shop!)

Glenn this is another option...,

https://www.rvwithtito.com/articles/portable-solar-panel-window-awning/

https://www.rvwaterfilterstore.com/custom-built-hoses

I guess you prefer not to shop on Amazon....

Just curious .... how do the numbers look so far?

True or false....Volvos’ motor oil pans are non-metallic?    

https://www.dexheavydutyparts.com

‭eight hundred two seven five five zero eight nine

https://www.technomadia.com

https://www.campgroundreviews.com/regions/washington

Glenn... is this the type of Air Dryer you have?

Schrader valve on the ‘governor.

http://photoposting.is-great.net/?i=1