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Old 05-16-2009, 07:00 PM
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DeliveryValve DeliveryValve is offline
Chairman of my Benz
Join Date: Jun 2006
Location: Central California
Posts: 4,144
Originally Posted by cessna5354 View Post
My cruise on the '83 300D does not hold speed, but rather when engaging the cruise with the stalk, the cruise will engage take over the accelerator.
But, it is up to warp speed... It never levels off, just continues to increase speed. There is no hesitation and the resultant acceleration is steady. I must cut it off manually, both the stalk & brake will cut off the cruise.
If your speedometer needle is steady (you have a new cable or your cable is properly lubed), then I believe the mostly likely caused is by a faulty cruise amplifier.
Or the cruise actuator is worn at a certain speed and it is searching/hunting for a better contact point. As shown in this pic.

Originally Posted by cessna5354 View Post
Where is the speed feedback come from. I believe there is a signal generated within the speedo/instrument cluster. Is this the signal I am missing??

I have a line on a instrument cluster takeout and was thinking of getting the cruise operating once again.
Here is a shot of the speed sensor, the black box in the back of the cluster.

I don't think you need a whole new cluster. But there is a possibility the speed sensor could go bad.

Here are some helpful links in Dx it. (look for the cruise control section.)
Attached Thumbnails
Cruise Control Feedback Signal-cruiseactuatorwornboard.jpg   Cruise Control Feedback Signal-clusterspeedsensor.jpg  
1983 123.133 California
- GreaseCar Veg System

Last edited by DeliveryValve; 05-16-2009 at 07:05 PM.
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