'84 300sd Why is my cruise control disconnected
 

Hi folks,

When I bought my '84 300sd a few months ago, I noticed that the rod connecting the cruise control actuator to the "throttle" linkage was missing. Any ideas why? I presume the cruise control must have a problem that makes it dangerous to use.

Thanks

I've never met anyone with a working cruise control on the older models. A lot of them had problems right from the beginning. It's likely that yours doesn't work and like you said may have been causing odd issues that could cause safety concerns. I personally wouldn't bother messing with it. But others might say otherwise.

Most of the issues are in the cruise amp under the dash. Sometimes all they need is all the contacts to be re-soldered.

Mine was disconnected too, I have heard stories of the cruise control sticking and causing a dangerous situation, so I dont intend on trying to fix it.

Hmm. I have a 12 hour drive to make this spring, and I'm not too keen on the idea of using my foot the whole way. Does anyone know anything about diagnosing the system? Is it worth it to open up the amp and resolder the connections, hook up the cruise control actuator and give it of shot?
Thanks

Usually, they can be repaired fairly easily but here's the glitch....if you try to do any resoldering,etc.. the repair facilities won't touch them. The best route is to send the amp to either of these places, for a little over $100 and be done with it:

ProgRama 003 545 86 32 Mercedes Benz Cruise Control

General Development Laboratories - Table of Contents

Both websites have troubleshooting suggestions they recommend. As mentioned earlier, it is most likely the amp but it is best to verify nothing is wrong with the servo as well.

If funds are severely limited, there is information available but keep in mind what I mentioned earlier.

GDL is your best bet. But an amp rebuild will cost considerably more than $100. A Programa rebuilt unit is cheaper, but arguably not as good. Actuator with that kind of low mileage is probably OK....but no guarantee.

Ideal approach is to send both actuator AND amp to GDL for evaluation and take it from there.

Wow! I just went to the pricing page for GDL and they have gone up significantly! The last I recall was about $139.

Sorry for the misleading pricing info!

Thanks for the info, folks. One other detail: when i try to engage the cruise control with the steering column stalk, I don't get any light on the dash. Does this indicate anything further? I am going to test the resistance on the amp, as the Programa website suggests.

I didn't know there's a cruise control light...I don't think I have one on either of mine.

74baja, to my knowledge, not even the later 126's had a CC indicator light. So I doubt your '84 SD has one.

Ah, alright. That explains it. Thanks.