Does any one out there have the procedures for diagnosing the cruise control in a 1984 300sd, not just checking the fuse and linkage!!!!!! The plastic gears inside are fine. I drive about 1000 miles a week and would like to get this working. Thank-you for any help.

You can test the motor part by using jumper wires to put bat voltage, one way moves the control arm out, switching polarity moves the arm the other way. Check the wiring diagram for the pinout. If that works, the control box under the dash above the brake pedal would be my next step. I bought a good working one on ebay for $25 last month. That fixed mine.

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85 300 SD ~ 115K
82 500 SEC Euro ??K
78 450SL 164K

I would lay money that the cruise amplifier under the dash is at fault.

But do test as "jimandsuzy" pointed out.

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I'm not a doctor, but I'll have a look.

'85 300SD 245k
'87 300SDL 251k
'90 300SEL 326k

Six others from BMW, GM, and Ford.

Liberty will not descend to a people; a people must raise themselves to liberty.[/IMG]