I'm troubleshooting electrical gremlins in my 1983 MB 300D. The rear defrost and console lights don't work.

I've replaced all the fuses. I've replaced the console bulb. I've verified the rear defrost is wired.

Maybe a relay is out? How many relays are there in this car? Are they fairly straightforward to replace?

Are there other troubleshooting tips for this type of gremlin?

TIA,

JJ

__________________
-------------
1983 MB 300D - 354,000 miles - "Blue"
1985 MB 300TD - 172,000 miles - "Yellow"
2000 VW Golf TDI - 149,000 miles - "Red"
All B100 powered