Cruise Control W124

[Orlando 300E]

Hello,
My cruise control sometimes hunts around for the correct speed & sometimes cuts out (usually after driving through pot-holes or over bumps).
Have read that the usual fault is the cruise control "Amp" -solder degrading or coming loose.
Also read that this circuit board can be re-soldered -is this straightforward? (Not well practiced with a solder iron!)
If it is not simple, how much do replacements cost?
My final silly question, where is it on my wagon! :? -Suspect it is under black plastic panel below carpet at front of passenger foot well.
Your guidance is appreciated
Cheers
Orlando

 

[shellgrip]

Cruise control.

Orlando, did you get anywhere with this? I have a related (though different) problem with my W123 (280TE). There is no visible switch for cruise control but I've found the transducer on the speedo which, according to the manual is only fitted when CC exists. What does the switch/control look like and where is the actuator/control unit?

jack :-#

 

[Orlando 300E]

Hello Jack,
I have had no response from my post .
The switch for the cruise control is approx. at 2 o'clock behind the steering wheel & above the control "wand"!
I believe that the actuator that adjusts the throttle during CC is located beneath the inlet manifold -reasonable sized lump of metal (have not inspected in great detail -it isn?t broke!).
Good luck
Orlando

 

[Robby Ackerman]

Orlando

The amp is usually the problem. However, when my amps have failed the unit simply didn't work period. The cutting out when you hit a rough spot may be due to something else such as the cutout switch on the brake pedal being too close to the pedal. Hunting or surging may be a result of accelerator control rods that are tight because then need some lubircation. I typically use ATF on my friction points. As far as soldering in the amp, you can remove it, open and visually look for broken or loose connections in the printed circuit board. Soldering is self-explanatory just don't use excessive heat. I don't know what amps sell for in the UK but rebuilt units on my side of the pond start at 85 pounds with new units selling for twice that.

 

[Orlando 300E]

Cheers Robby!
O.

 

[Leylandp76]

I'm interested in this issue, the CC on my 300TE is jerky too. I'll try lubricating the friction points as suggested. It has been suggested that worn rubber couplings on the drivetrain will make it worse too.