Hey everyone, recently I helped my sister in law buy her first car, 91 300e wagon 4matic. Pretty clean car, but had a few issues.
The issues so far I’m seeing are all electrical.
-Blower isn’t working any speed
-Front wiper isn’t working on any speed
-Dash lights and cluster lights don’t come up on
-the warning buzzer makes a slight noise at all time then stops when the turn signal is on. But comes back when turn signal is off

I recently swapped the coolant tank as it had a leak and while there I replaced all the fuses, as most were the wrong ones. Doing this the windows started to work, the rear wipers now works. But the other problems are still there.
The lights in the switches I notice slightly pulse very dimly so I’m assuming that issue is the knob in the cluster is the problem.
But for the other two main issues, is there a common relay that supplies these that may be the issue? I know they would both have their own to control speed. But is there maybe a main power or shared ground?
I did pull up the back seat and found a mouse nest so I’m hoping i don’t find a bunch of chewed wires.
Any help would be greatly appreciated