2002 E825 electrical gremlins

Looking for some help. I have a 2002 E825 four seater with lead acid batteries, and on its third Zivan stock charger. While changing chargers and testing, I noticed that a fuse was blown, (bottom row, third across). When replaced, the left turn signal indicator lit, as did the left front amber turn signal. I say this because the rear bright filament on the left side does not, the small one meant to be the rear marker or parking light does. The lights do not flash when the left turn signal is activated, nor do the hazards flash when the leaver is pulled. The left rear bright filament also doesn’t light when the brakes are applied, the low filament does. The low filament lights when the headlights are turned on, but then goes out when the brakes are applied with the headlights on. Again, the bright filament on the left side rear never lights up. The right side lamps all work as expected. Anyone have a suggestion as to the cause? Could the turn signal module be at fault? Or a deeper controller issue? I have also noted that the reverse light and the license plate light no longer light up, and my multimeter shows some current to each, but not enough to light the lights. Swapping bulbs had not been effective.
Thanks in advance for your ideas.

You know what gets rid of Gremlins? Bullets. Fire. Bulldozers and rocket fuel are great at making sure the fvckers stay dead.

Lets start with your dc-dc converter. Its under the dash, in front of the passenger. Is it a black bix, a silver box or a potted circiut board.

Also run your vin through the recall database at nthsa see what shows up.

The dc to dc converter is a black box.

Whenever crazy symptoms like this show up(especially when it comes to lighting), I always first look/check the grounds. the harness has a junction back at the batteries that are a 2x2 molex plug. This is an unsealed connector and exposed to nasty elements. make sure this is nice and clean and power going through it. The backup light has it’s own connector.

There is another one up forward that the headlights, marker/turn sigs go through so you can detach the hood. Look for melted/discolored plug which is a sign of heat and a bad connection.

Once connections are verified good, double check that your tail light bulbs were inserted in the sockets correctly. They might have been forced in backwards. The early cars were based on a resistive flasher and the wimpy running light filament may not draw enough current to heat up the flasher and it won’t go click.