cruise control problems
 

i am having cruise control problems with my 84' 300cd. sometimes it works, but usually it doesn't. when i move the lever upward to set/accelerate it will accelerate the car but when i release the lever the cruise control does not engage. :(

Mark,
Do a search on here on cruise control - your problem sounds pretty typical. More than likely the amplifier.

Your symptoms sound exactly like those on my 300cd. Replaced the amplifier and it works great.

Blocking the air recirculation valve on the turbo units have helped me get rid of the surges on my 300D turbo 1985. But I would like clear the fact that i did not have any problems with setting or engaging the cruise control. It was the surges that were driving me insane.

MVK

where is the amplifier located and how difficult is it to replace. i am mechanically inclined but the car is new to me. thanks for all the help

first think I always check, make sure you have german bulbs in the tail lights meaning they better have a silver bottom. Copper and brass, throw them away.

Then go from there.

Re: bulbs....http://www.gdl-online.com/bulb.html


Good Cruise reference:...http://www.gdl-online.com/begin1.html#contents

the resistance of the bases are different.

Well when I change the bulbs to german ones it always works. You can read about it or do it. the choice is yours.

On my '81 300CD the amplifier is above the steering column near the firewall. It is silver in color and appr. 4" x 1" x 5". It is easiest to remove the "strap" from the car and then the strap from the amplifier. There is a ten wire connector attaching to the system. Yous may have more or fewer wires going to and from the amplifier.

The bulbs will affect the cruise control only when interupting when you brake. It is necessary to have European bulbs in the brake lights. They are available at the McParts stores.

I hope this is of some help. I have tried to be accurate in description, but it's been awhile since I've worked on this.