Accessing my 126's cruise control amplifier

[goldstone]

Having read all the posts relating problems and guidance on cruise control amplifiers over the months, I considereded myself lucky given the flawless performance my '89 420 SEL has provided in this area.

Well, this weekend, my luck ran out and I now feel your pain... The classic symptoms I've read about here are now afflicting my cruise control: pretty constant surging coupled with periodic (unexpected) disengagement.

Anyway, I'd like to try some of the recommended fixes before conceding defeat and buying a replacement; but I need to get at the amplifier and don't know how. (I believe it's located behind my dash on the driver's side, but what's the best/easiest way to get to it for easy removal and repair?)

The advice of experienced 126'ers would really be appreciated (as always).

[rbmercedes]

It's easy, and it takes less that 15 minutes to remove. Unscrew the knee bolster and trim, and you'll find the amplifier above and to the left of the steering column. Its a brushed aluminum box with a long plug on the bottom. It has a bolt and nut, so you may need two wrenches (use 11mm socket/wrench).

The warning buzzer is attached to the CCA bracket as well, so this is your opportuniy to disable that too, if you wish.


Good Luck!

RBM

ps. I purchased a reman unit from a company in San Diego which I found in Hemmings. $129 for a unit with a three year warranty.
I don't have the company name handy, but you can go to hmn.com and search for cruise control amplifier.

[goldstone]

Thanks for answering my main question (i.e. getting to the unit.)

Now, my follow-up: Can I drive the car with the amplifier removed?

If "Yes", I can carry out the repair attempt/replacement at a leisurely pace; if "No", then I'll need to schedule surgery more carefully!

[jrfreeman]

There is no problem with the cruise control amp being disconected and the car driven. My is on the bench right now. HTH

[goldstone]

I've learned so much (and accomplished a lot too) based on information shared by others on this forum; but sometimes I feel totally inept!!!

I decided to get my malfunctioning cruise amp out over the weekend to be either repaired or replaced. Above, rbmercedes assured that it would take "less than fifteen minutes"; clearly, he didn't know whom he was advising

I removed the "knee bolster" under the dash--no problem. But right there, precluding my accessing the amp, is a black metal barrier. I realize there must be an easy way to get past it, but having never needed to go further before for any reason, I simply don't know what to loosen next.

Any 126 owners who can get me where I need to go???

[MikeTangas]

If I'm reading this correctly, you've pulled the underdash and are now looking at a large black can that runs the width of the driver's side of the dash. That is actually the bolster. If I remember correctly there are three nuts/bolts that hold it in place, one at each end and the third hidden inside the can. Look in the access hole about the midpoint, you'll see it. Don't have to remove that one, just loosen it.

But as I recall, one doesn't have to remove the tube, only the underdash. Once the underdash is out of your way lay on the floor and you;ll see the cruise amp bolted to the brake pedal pedistal. !0mm box wrench is all you need to remove the single nut. Upon reassembly you'll need both hands, one to hold the bolt in it's recess and the other to start the nut.

[jbaj007]

The cruise control amplifier and the control module (smaller aluminum box) are attached to a gold anodized bracket that attaches to a black metal strut. You want to unbolt the bracket from the strut, disconnecting both boxes with it (you'll see why; you can't get to the rear screw to the CC amp w/o removing the bracket). It is a 10 mm. hex head that attaches the bracket. On many, the "nut" is part of the bracket and does not turn. The 10mm. hex head bolt is on the other side in a recess that requires pushing on a rubber "accordian" to access. Feel with your "pinkie" (deep) and you'll find it. A deep socket helps to keep alignment on it as you fight the "accordian".

[goldstone]

Thanks for the help, Mike!

I've been looking along the steering column for the amp, but will redirect my attention to the brake pedal as suggested.

----> By the way: I finally had a chance to go back and read through your absolutely awe-inspiring 560SEL restoration thread. A very belated congratulations and a big thank you for all of your helpful posts on this board!

[goldstone]

And thanks (as always ) to jbaj007!