W126 aftermarket cruise control

[944S2cab]

My daily driver is a 1991 W126 300SE and the one thing I miss is cruise control. To buy all the individual components from Mercedes would probably cost half the value of the car, if they are all still available.

Has anyone fitted an aftermarket cruise control kit to a W126? If so, which one and was it successful?

Thank you.

 

[ianrandom]

My daily driver is a 1991 W126 300SE and the one thing I miss is cruise control. To buy all the individual components from Mercedes would probably cost half the value of the car, if they are all still available.

Has anyone fitted an aftermarket cruise control kit to a W126? If so, which one and was it successful?

Thank you.

You could get the bits used? I hadn't realised before, but some of these cars were retrofitted at the dealer when new, which is a bit odd. It turns out my SE is one of these, identifiable by the servo being cable driven and mounted in a different place.
It's a pretty simple system really.

 

[944S2cab]

Thank you.
I had thought about used parts. My parts diagram shows more than 30 components. Certain parts are available on ebay at certain times, so I would have to obtain them over a period of time. I could improvise for some parts (brackets, bolts etc) but as I don't have a wiring diagram for cruise I could not build the wiring harnesses. I've not seen any cruise harnesses on ebay yet.
A classic Mercedes breaker may be able to supply all the parts in one go if I am lucky.

 

[Andy_C]

I appreciate that the kit is for a W124, but, apart from the cruise switch, there can't be much difference between a W126 and W124. The cruise circuit is quite easy: speed input from a Hall sensor on the back of the speedo, power,and an input from the brake light switch.
TEMPOMAT KIT COMPLET MERCEDES W124 COMPLETE SET KOMPLETT REGULATEUR DE VITESSE

Andy

 

[219]

It really is a very simple retrofit , and the system is very similar on W201 , W124 and W126 .

All my W126 cars had cruise , but I did retrofit it to a W 124 once .

There are basically three or four components , depending on the car .

The steering column stalk

The cruise control amplifier - the amplifiers are basically all the same , but there is a coding plug attached which optimises the system to different vehicles , although it will still work with the wrong one .

The throttle actuator - these differ from one engine to another , so you need to get the right one for your engine - on the M103 it sits right at the front .

Some cars require a Hall effect sensor fitted onto the back of the speedometer ; cars with electronic speedos , like W126 , don't need this .

You also need the wiring loom to connect these parts together .

The best way is to find a donor car with the same engine as yours , this will be either a W126 300SE , or a W124 300E/CE/TE in your case , and strip all the parts from it yourself .

It takes a bit of time to follow the wiring loom and unpick it without cutting , but it is possible . It links the speedometer , control stalk and the amplifier above the drivers footwell , and runs to the throttle actuator at the front of the engine . If you take your time you can unpick it from the donor car without damage and fit back into your own car .

Make sure to get all mounting brackets and extra bits of throttle linkage needed to fit and get it all working .

There aren't so many of these cars in breakers these days , but still plenty breaking for spares on eBay .

 

[944S2cab]

Thank you very much for the information.
Sorry for the delay in replying. I've not looked at the forum for a few weeks.