Complete electronics shut down

[vtl]

Make a VIDA screenshot with all the errors you see and post it here.

[volvolugnut]

The heat shrink tubing can also be used to protect soldered splice joints. These plastic tubes must be placed on the tube before soldering and then heated to shrink to fit.
I agree, your wiring from battery to engine seems compromised.
volvolugnut

[imaV70Rdriver]

@ firstv70volvo, you made mention of the 60amp fuses on the bottom side of the fuse panel located under the hood. I cleaned all contact surfaces and all fuses had the same resistance. I did this about a month ago and don’t recall the values. But they seem to be fine.

@jonesg, I’ve been looking on EBay for automotive meters, (a daunting endeavor), and wonder if you (or anyone else) might comment on the mandatory features needed for proper automotive troubleshooting. Do you see anything that you would buy, among the top 15 listed (which are close to my location) at this EBay link? If it’s not too much to ask.

https://www.ebay.com/sch/i.html?_dcat=5 ... _sadis=500

@vtl, I concur, the connections are subpar no doubt. Done hastily and improperly, but they lasted nearly five years. As I said, a new harness is on the way. Attached are three screenshots of VIDA, one showing communication to the modules, then my dashboard showing no gauges working while the car is running, and the third one is VIDA fault-tracing. The panel in the ceiling, that illuminates the rear when the tailgate is open, has been disconnected.

@jonesg (again), I will disconnect the red lead from the battery and check resistance between the battery end, and the +ve under the hood, and report back.

[jonesg]

Some of those meter have amp clamps, I wouldn't know how to use one, I also wouldn't know what the results mean.
SO my preference is to keep it simple.
I bought this innova from an auto part store, its simpler to use and more suited for my car work.
The built in load tester are handy for our 12v car batteries. Cheap at $32. They've sold almost 8000 units and it has good reviews.

https://www.amazon.com/INNOVA-3320-Auto ... 71&sr=8-16

[jonesg]

As for the odd readings from the Foxwell battery analyzer (oddly, also called “BT100”) in the photos above, it seems that the device only reads the battery properly when connected directly to the battery, because it reads “replace battery” (even with a brand new battery) when connected to the +ve terminal under the hood, but who knew.
Next things to do… get the DIM repaired, and chase down the (probable) wiring issue related to the intermittent “tailgate open”.

No I think thats telling you either the 12v cable is faulty, or theres a huge parasitic draw....or both.
My money is the parasitic draw, it should be in the milliamp range, but yours is a high amp circuit shorted to ground.

2 yrs ago...or was it last week ?...I had that same tailgate open message on the dash and alarm actuation, its silent because I disconnected the alarm yrs ago. It turned out the tailgate glass defroster wire was disconnected from the heater wire on the glass.
a little soldering got it connected again and the tailgate warning went away. So the heater wire is part of the alarm circuit.
THe battery isn't drawing down because the alarm is triggered, its the glass defroster short causing the big loss.
That short is a big power draw because its a resistence heater, the wiring is capable of feeding lots of amps.

Under normal conditions, if everything is on they will all shut off when starting the engine so the starter gets clean 12v power by design. A load test at the battery post will show the parasitic draw.
Fix that and verify the 12v battery cable is good, the problem will be fixed.