Adding cruise to a non cruise car - PeachParts Mercedes-Benz Forum

t walgamuth · #1 01-17-2014, 02:40 PM

My 82 240d now has the "new" motor installed that I bought from VStech. It runs good and all but the cruise control situation is a bit murky. My Indie says the the car has all the wiring under the hood but lacks the stalk on the steering column. Can someone tell me what needs to be done to get that working? Is it possible to just add the switch? I don't know if it has the electronic box under the steering column or not.

Mölyapina · #2 01-17-2014, 05:33 PM

Does the engine come with an actuator? If it does, then is it hooked up or not?

As far as the wiring at the switch, the CC switch is tacked onto one end of the combination. Here it is in situ -- those four screws are holding the switch in.

The circled plug in the picture is the connection for the CC switch under the dash. The big silver box with the yellow bottom is the cruise unit.

The wires slide right out of the steering column:

...and this is how the switch makes it out of the bigger assembly:

Mölyapina · #3 01-17-2014, 05:36 PM

The one other thing you should check is the rubber collar that goes around the switch area. The CC cars had an extra little hole for the switch like so:

KCM · #4 01-17-2014, 05:36 PM

When I bought my 240D, I thought at first it did not have cruise control. Turns out that somebody broke off the handle. Installed a new used switch as shown above and all was good. Maybe somebody broke the handle off of yours too.

Mölyapina · #5 01-17-2014, 05:48 PM

^^My thought also.

jay_bob · #6 01-17-2014, 08:52 PM

The system has the following parts:

Actuator - on the engine.
(Note: If you got my old actuator with the motor from Vstech, I believe it was dead. There is a broken solder joint inside, on the motor circuit, that I could not figure out how to fix, since I could not figure out how to disassemble the actuator internally to reach the point that needs to be soldered.)

However you can check out potential donor actuators in the junk yard with a multimeter, a 12 V drill battery, and some clip leads.
Feedback pot:
- Check pins 1-3, should have about 3.5 k ohms (3500 ohms) always
- Check pins 1-2, should go from 3.5 k ohms to zero as you rotate the shaft
- Check pins 2-3, should go from zero to 3.5 k ohms as you rotate the shaft
I cannot remember which way is which, but it should go one way from 1-2 and the other way from 2-3.
Motor:
Check pins 4-5, should have a few ohms resistance
Jump drill battery power to pins 4-5, the motor should whir. Put your meter on amps, in series with the battery and the motor, make sure you are under 200 mA (or 0.2 A).
Solenoid:
Check pins 6-7, should have a few ohms
Jump battery power to pins 6-7, you should hear solenoid click.
Do not jump 4-5 and 6-7 to power at the same time or you will damage the gear train

Vehicle Speed Sensor:
On the back of the speedo, little black thingy that says VDO on it, with a connector, right around where the speedo cable goes in.

Amplifier:
Under the dash as shown in Joseppi's picture. It is secured with a bracket to the brake pedal. Don't remove the two Phillips screws, look straight up from below, you will see a 10 mm nut and bolt, remove that, and the amp will drop right out. JamesDean rebuilds them.

Stalk:
In the column ahead of the combination switch per JL's picture. They often are broken off.

Also verify you have properly functioning brake bulbs. The engagement permissive relies on the control lead from the amplifier, which connects to the brake light line, being at ground potential when you are off the brake (via the filaments in the brake light bulbs to ground) and at 12 V dc when you are on the brake (since there is now 12 V applied to the brake circuit when you step on the pedal).

If you are going manual you will need a clutch switch, so that it dumps the cruise if you push the clutch in. This switch should be on the clutch pedal assembly already if you pulled the manual from a car with cruise.

Operation in a nutshell:
Accelerate to 35+ mph, push the stalk up and hold until you feel it engage then let off the pedal
Push stalk away from you to cancel (or step on the brake or the clutch)
Pull stalk towards you to resume
You can vary the set speed up or down by pushing the stalk up (faster) or down (slower).

t walgamuth · #7 01-17-2014, 11:16 PM

Cool! My indie says there is no hole indicating a broken off cruise stalk. I'm too tired to sort this through tonight, but thanks very much for all the detailed information!

cooljjay · #8 01-19-2014, 10:14 PM

I add cruise control to my car for 8$.....

I got tired of trying to fix my cruise control.....so I went and bought a throttle control cable....installed it in place of the factor adjuster...now I can idle the car for easier cold starts....then I can pull it out to set the throttle for cruise on the freeway....works awesome!

t walgamuth · #9 01-20-2014, 10:36 AM

Quote:

Originally Posted by cooljjay

I add cruise control to my car for 8$.....

I got tired of trying to fix my cruise control.....so I went and bought a throttle control cable....installed it in place of the factor adjuster...now I can idle the car for easier cold starts....then I can pull it out to set the throttle for cruise on the freeway....works awesome!

of course in a panic stop you need to remember to push in the throttle.

JamesDean · #10 01-20-2014, 12:02 PM

To add to the list, you'll probably also need an actuator and some linkage pieces. Pretty much any actuator from 82-93 should do. They are all compatible, they just need to be mounted differently and have arms changed based on the application.

Not sure about the linkage though.

Compatible cruise amplifiers are:
001 545 79 32
002 545 32 32
002 545 91 32

Stevo · #11 01-20-2014, 12:34 PM

A couple years ago I went with the Rostra Electronic Global Cruise System. My Euro TD had never had a cruise so from a parts car I added the OEM stalk and speedo pick up. It works fine and looks stock.