Fitting cruise control from a 1984 300D US into a 1981 300TD Euro Turbo w/automatic? - PeachParts Mercedes-Benz Forum

Mölyapina · #1 04-09-2013, 06:42 PM

...so Devi, a member here who lives in Finland, sent me a PM asking for some cruise control parts from me -- the switch on the column, the mount for the actuator, and the linkages running from the cruise control actuator to the accelerator linkages. She pulled her system from a W124, so not everything matches.

Here is a picture of her underhood (wish mine looked like that...):

And here is the linkage that I have (not my car, I stole this image from that "world of 'Benzes" (

) because mine is in pieces):

What all does she need from me, linkage-wise, to make this work? Also, will the module from a W124 work in her car? Is there anything else being missed here? Why do I appear to have a Bowden cable while she doesn't?

pawoSD · #2 04-10-2013, 07:39 AM

Getting that working will be a wiring nightmare, the W124 setup will likely not work. Easiest way would be to use an aftermarket system like the audiovox ccs-100. I have that on my SD and it works flawlessly. You can use the original control stalk also so it looks perfectly stock.

charmalu · #3 04-10-2013, 12:08 PM

There are actually two different after market Cruise Control units that have been discussed. the Rostra and the Audiovox CCS-100.

Rostra Global Cruise Install Thread

Rostra Cruise Wiring diagram

The Official Audiovox CCS-100 Install Thread

Hope this helps.

Charlie

JamesDean · #4 04-10-2013, 12:28 PM

Its possible.

The hardest part will be running wires and what not. The typically the cruise control amplifier sits under the dash. It makes connections with the following:

(and this is true for all of the cars equipped with the 14-pin cruise control)
1) Power/Ground
2) Actuator in engine bay
3) stalk on steering column
4) brake pedal switch
5) vehicle speed sensor at back of cluster (different for 126)

The 124's cruise control harness might not be long enough in needed areas. So might need to lengthen it..other than that..i dont think its impossible.

Its do-able however provided there is time, parts and patience.

It seems that the 123's mount hat one linkage assembly higher up/closer to the radiator than the 126's so you might need a shorter rod to go between that and the blue rectangle piece.

It looks like you'll need to send her the actuator/actuator mount and one piece of linkage:

As for a cruise amplifier, i think the applicable part numbers would be
001 545 79 32
002 545 32 32
002 545 91 32

Mölyapina · #5 04-10-2013, 01:18 PM

Quote:

Originally Posted by JamesDean

It looks like you'll need to send her the actuator/actuator mount and one piece of linkage:

Actually, when I suggested that, she pointed out that the thing that looks like the point one would connect cruise to is a straight peg (no ball on top).

JamesDean · #6 04-10-2013, 01:28 PM

Quote:

Originally Posted by Jooseppi Luna

Actually, when I suggested that, she pointed out that the thing that looks like the point one would connect cruise to is a straight peg (no ball on top).

Oh you mean the upper connector just below those two ball connectors is actually just a peg and not a ball?

Mölyapina · #7 04-10-2013, 01:42 PM

Quote:

Originally Posted by JamesDean

Oh you mean the upper connector just below those two ball connectors is actually just a peg and not a ball?

Bingo!

whunter · #8 04-29-2013, 10:15 AM

Sorry for the delayed answer.

Forget the factory cruise control, it is trash compared to any modern after market unit.

Even if it where wired into the car, at best it would be a constant failure point.

The only way I work on the old factory system is to replace everything at the exact same moment, with rebuilt.
Even then I will not guarantee the system, only the labor.

.

JamesDean · #9 04-29-2013, 10:26 AM

Quote:

Originally Posted by whunter

Sorry for the delayed answer.

Forget the factory cruise control, it is trash compared to any modern after market unit.

Even if it where wired into the car, at best it would be a constant failure point.

The only way I work on the old factory system is to replace everything at the exact same moment, with rebuilt.
Even then I will not guarantee the system, only the labor.

.

I respectfully disagree.

I do not believe the system to be trash. I've put on nearly 15,000 miles on my 300D with the cruise activated for nearly 95% of those miles as my commute is nearly all highway at 70 MPH. My 190E's cruise control repair is now 1.5 years old and still works flawlessly. It has about 10,000 miles on the system.

I think you might be getting trashy rebuild units, especially if what I've seen from "rebuilt" units is true.

I've only examined a total of three or four rebuilt units, from "CCI Uptime", "ProGrama", "Beckmann" and "PerformanceProducts" and ALL of them have failed to replace factory original components (electrolytic capacitors) components that would fail in a short length of time. It seems most of these repairs have been "get it working" type of repairs and not "actual rebuilds." This is what I've seen with the few units that were rebuilds that have come across my workbench. I cannot say this is true for NEWER rebuilds.

Here is an example of a trashy rebuild.
Cruise Control Amplifier Diagnostics & Amplifier Repair

You can see that ProGrama did not replace the original (25+ year old) electrolytic capacitors, nor did they re-coat or re-solder the entirety of the board. They also falsely labeled the unit as an "002 545 91 32" when in fact that unit is an "002 545 32 32." While BOTH will work in W123 diesels they are not in fact the same item from a part number / technical stand point. The 91 32 unit has a different board layout and uses some different parts here and there.

I've shipped/sold/repaired about 210 units so far and I've only about 3 return/repair issues so far.

Basically, as long as
1) the amplifier is properly rebuilt
2) The actuator current draw is below 220mA
3) The speed signal is clean (no bad speedocable)

The system should work as intended and this has been my experience over the past year and a few months now. I've many happy customers.

whunter · #10 04-29-2013, 10:58 AM

If everything is in spec, they are acceptable.

Unfortunately my experience shows that most used units are failing for various reasons, and even the rebuilds can have issues (as you point out).

If you went through them before the install my view would be different.

The second issue is the work to alter her vehicle to make these work.

IMO it is more cost effective, and much less work to install an after market cruise control on this particular vehicle.

.