The 1986+ cars are very different from the earlier cars. The PBU is full of electronics. Opening the unit and unclipping the PCB's will get it to where you can work on it yourself. Resoldering is a DIY job if you know how to solder.

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Current stable:
1995 E320 157K (Nancy)
1983 500SL 125K (SLoL)

Gone but not forgotten:
1986 300SDL (RIP)
1991 350SD
1991 560SEL
1990 560SEL
1986 500SEL Euro (Rusted to nothing at 47K!)

Gone and wanting to forget:
1985 524TD 167K (TotalDumpster™) [Definitely NOT a Benz]