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-   -   HOW-TO: Cruise Control Amp Repair 14-pin (http://www.peachparts.com/shopforum/tech-help/313824-how-cruise-control-amp-repair-14-pin.html)

BenzEnthusiast 03-19-2017 05:38 AM

Surging...
 
Has anyone had any experience with their cruise control working, as in it holds the correct speed and everything, except it surges? It's like the throttle inputs are not very smooth. It has done this with the 2 different actuators I have tried.

Could it just be the amp giving up? I wanted to get your opinon before I cracked it open to try to repair it.

shertex 03-19-2017 05:46 AM

Quote:

Originally Posted by BenzEnthusiast (Post 3693421)
Has anyone had any experience with their cruise control working, as in it holds the correct speed and everything, except it surges? It's like the throttle inputs are not very smooth. It has done this with the 2 different actuators I have tried.

Could it just be the amp giving up? I wanted to get your opinon before I cracked it open to try to repair it.

Yes. When that happened to me the cause was a bad amp.

BenzEnthusiast 03-19-2017 12:50 PM

Thanks for the info. I wasn't sure if they could fail in that manner. I guess I'll be ordering some new parts for it.

tinypanzer 03-22-2017 07:12 PM

I have only once ever had a w126 module fail that couldn't be repaired by either re-soldering cracked joints, or replacing aged electrolytic capacitors.

Of particular importance when you replace the capacitors is to choose ones with the highest temperature rating possible. 105C should be the minimum temp rating for automotive use. Also, be sure to observe polarity!

okyoureabeast 03-23-2017 01:03 AM

Good thread, i'm in the process of getting my cruise control to work.

Hilariously, I can make the car move faster with the cruise stalk but the speed never sets which leads me to believe it's a bad amplifier.

I'm going to go to the salvage yard tomorrow to try and pick one off of a car. Here's hoping I can find a good one!

Clemson88 12-25-2017 02:20 PM

The first of the capacitors listed came up obsolete on Mouser's website.
 
I'm not confident I can choose workable alternatives. As always any help is much appreciated.

I'm aware the OP here is very old so if anyone can share their opinion on a particular brand of capacitors which have longer lives that would be fine too.

JamesDean 12-25-2017 03:30 PM

Hi Clemson!

Here is an updated list of capacitors:

For the 22uF units:
https://www.mouser.com/ProductDetail/647-UPW2A220MPD

For the 10uF units:
https://www.mouser.com/ProductDetail/647-UPW2A100MED

For the 2.2uF units:
https://www.mouser.com/ProductDetail/647-UPW2A2R2MDD

These are all radial type capacitors but the leads are long enough such that they can hit the holes on the cruise amp boards!

BenzEnthusiast 12-25-2017 03:35 PM

Thanks for the new information on the capacitors. I still haven't gotten around to fixing mine yet.

Grzpdlr 12-25-2017 03:41 PM

Quote:

Originally Posted by BenzEnthusiast (Post 3775501)
Thanks for the new information on the capacitors. I still haven't gotten around to fixing mine yet.


My two cents, send it JamesDean, he'll fix it right for a very reasonable price.

Clemson88 12-25-2017 03:58 PM

You guys should know me by now.
 
Quote:

Originally Posted by Grzpdlr (Post 3775502)
My two cents, send it JamesDean, he'll fix it right for a very reasonable price.

I'm old and have nothing to do but piddle with my car. I know that I could have gotten a great job from James Dean and I'll probably spend more on the workstation than he'd charge.

I could have gotten that PS gearbox rebuilt by a trusted member here, a good set of injectors from another and probably found a member who would have done the wiring for me when I put the 617 in the gas body.

What would I have done for the last two years had I not wasted them learning to repair my own stuff?

Clemson88 12-25-2017 04:02 PM

Look at you!
 
Quote:

Originally Posted by JamesDean (Post 3775499)
Hi Clemson!

Here is an updated list of capacitors:

For the 22uF units:
https://www.mouser.com/ProductDetail/647-UPW2A220MPD

For the 10uF units:
https://www.mouser.com/ProductDetail/647-UPW2A100MED

For the 2.2uF units:
https://www.mouser.com/ProductDetail/647-UPW2A2R2MDD

These are all radial type capacitors but the leads are long enough such that they can hit the holes on the cruise amp boards!

Thank you, JamesDean. That's kind of you and I'm obliged.

vwnate1 02-19-2018 11:34 AM

Subscribed

KJZ78701 01-19-2019 05:24 PM

If I may suggest:

I checked all six caps before ordering new ones.

You can check the four axial caps but popping one side. The two radials do need to be removed completely.

In my case, they all speced even though the cruise control was not working. After checking/verifiying specs I soldered them back in and also resoldered the transistors, which looked a little suspect. That's all I did, and the cruise control came back to life.

IF the caps last at least 1000 hours and you use your cruise at 60 MPH, the caps should go 60k miles. If you use your cruise control 10% of the time....well, you do the math. :)


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