Installing Tempomat/Cruise Control

[floyd111]

Hi guys,

I have a European 1979 280S in the middle of a full restoration. It never came with a Tempomat or otherwise cruise control.
Even though I dislike mods that deviate from the original, this is one I need.
However, I am unaware as to what it takes to get there.

What type CC would a car like mine have had, had it been officially installed back in 1979? Tempomat, VDO?
What are the list of parts required for such a complete set-up?
Who might have such systems new or second hand?
More so, can a proper retro-fit be done without replacing major other parts?

Since the car is gonna come apart till the last screw, the hours involved in this mod are not to be counted(!)

All data is much appreciated.

Stan

[ptashek]

What are the list of parts required for such a complete set-up?
Who might have such systems new or second hand?
More so, can a proper retro-fit be done without replacing major other parts?

CC was available for the 280S, but only if combined with an auto transmission. The option code was 440, and it cost 452DM in 1979 (about 427USD in todays money).

1) Parts required would be: CC amplifier, vacuum actuator with throttle linkage, CC control stick, wiring loom, speed sensor. It's simple enough.

2) Re-conditioned amplifiers and used actuators are available on eBay for reasonable money, or new ones from MB for crazy money (~1200EUR for both, the last time I've checked). AFAIR, there's a trick to buying the actuator - if the resistance across its contacts is <12 Ohm, it's a dud. Any skilled electrician should have no issues with wiring it all together. The actuator linkage (i.e the cable) are NLA from MB, and there's no after-market options other than salvaged parts. You could probably have one made too.

3) I think it's a simple add-on, no major changes required. The W116 had no topographical sensor in the transmission, unlike the W26, making things even easier.

[floyd111]

wow, that's some proper data! Thanks so much for that.

Remains one thing.. I want my car to be as original as possible. I understand there were 2 different systems sold
What type CC would a car like mine have had, had it been officially installed back in an 280S Euro 1979? Tempomat or VDO?

[ptashek]

wow, that's some proper data! Thanks so much for that.

Remains one thing.. I want my car to be as original as possible. I understand there were 2 different systems sold
What type CC would a car like mine have had, had it been officially installed back in an 280S Euro 1979? Tempomat or VDO?

I don't think there are two systems. The entire setup was made by VDO. The name "tempomat" is simply "cruise control" in German.
There are two or three part numbers for the amplifier, depending on year and model (diesel and petrol models have different PNs).
The actuator was identical for all models AFAIR.

For some adventures of my own with repairing CC in a W116, check this thread: http://forum.w116.org/mechanicals/cruise-control-not-keeping-set-speed/
It has plenty of additional details on the setup you may find useful in a retro-fit.

[floyd111]

At this point I am about ready to go shopping for a used, new or rebuilt CC system.
Not cheap, so i want to make sure I get it right.

I see online a series of items, sometimes mentioning a common fit for  W123 / W116, or only W116 - only W123
What items belonging to the 280S W116 are W116 specific? What items are indeed the same on the W123?

Could anyone list the fitting W116 part numbers for the complete CC system parts?

Then there are the "Programa" modules on sale on eBay.
Anyone used those? Are there issues to consider?

[ptashek]

Could anyone list the fitting W116 part numbers for the complete CC system parts?

You may want to get access to the EPC
It's 20EUR/year and worth every cent. MB Club members get it for free with their membership.
Anyways, I think this is the complete list but please do verify.

CONTROL UNIT A0055451232
HOLDER, CONTROL UNIT A1165454040
CONTROL UNIT REGULATOR A0015450732
CABLE REGULATOR A1163001830
HOLDER A1165402973
THROTTLE LEVER A1100702624
SPEEDOMETER CABLE, 400MM A1075421407
TACHOMETER CABLE, 970MM A1165421207
SWITCH CONTROL UNIT A0045458624
SENSOR INSTRUMENT CLUSTER A0045422117
SENSOR SPEEDOMETER CABLE A0045420517
VALVE A1168000378
VACUUM RESERVOIR A1168000219
HARNESS A1165407509 / A1165409009

Then there are the "Programa" modules on sale on eBay.
Anyone used those? Are there issues to consider?

Haven't used one, but from what I know they're just re-conditioned and re-calibrated OEM amps, and of good quality.

[als450]

would these parts be the same for a V8 as well as a 6???