1994 E320 Wagon - Dash electrical short(s)- any suggestions

[BMG]

Problem

No dash illumination lights - rheostat does work and adjusts all the remaining knob and switch lights on dash. Fues appears ok.

Turn signal indicators on dash normal when running lights / headlights are NOT on. Lights flash correctly and relay clicks as expected.

When running lights (no headlights) or running and headlights are switched on, both turn indicators on dash illuminate partially as well as the high beams indicator. When I use a turn signal, both indicators flash and the relay does NOT click. I also noticed that the Tach needle drops 400 rpm every flash of the turn signal.

Turn off lights (running and headlights) and problem goes away.

I do get a trouble light indicator for lights breifly when lights turned on but it quickly goes out.

Two other items (probably unrelated); Fuel guage level does not work (low fuel light does work fortunately). Oil Pressure guage is maxed out once the key is turned on (probably bad wire in engine compartment - I see bare wires where it comes thru firewall - to be replaced this weekend).

Items Checked so far

Pulled dash unit and checked its onboard fuse - ok
bulbs for Illumination - replaced - no change
Fuses in engine compartment ok.


I cannot pull codes off this car yet. It would appear that one of the previous owners disabled the check engine light and the diagnostic unit in front of the battery. I have that on my list to troubleshoot this weekend as well


Any suggestions on the Dash short issue?


Thanks in advance.

Brian