Make sure the inline fuse buried in the fuse box (it's not one of the ones you can see) hasn't blown. Next most likely is the ACC, last would be the amp.

Good luck. I never could have serviced my ACC on my 80 450SEl without the manual. I just put it up for sale in the Parts forum.

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S, J.R. Brown
2000 G500 LWB Obsedian Black
2005 Toyota Tacoma Access Cab Off Road Sport
1993 Volvo 240 Sedan Anthracite
1980 450SEL Champange (owned it for 15 years. Great car)
1986 280GE LWB Anthracite (Sold it and kinda wish I hadn't)