on the 420sel, I used aluminum foil and red nail polish to "resolder" the ccu. It worked very well. On my ford van the steering column ignition switch broke so I cracked open the column to break the steering lock and started the van by pushing a rod that ran down the column. I stopped the engine by pulling the rod back up. The tilt mechanism eventually broke and I used zip ties to hold the steering wheel in a comfortable position to drive. I drove it this way daily for about a year until I decided to fix it.

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1984 300SD Orient Red/ Palomino
1989 560SEC
2016 Mazda 6 6 speed manual
1995 Ford F-150 reg cab 4.9 5speed manual