Criuse control??
 

My 84 Carrera has cruise control, but doesn't hold consistent speed. Keeps dropping back. Anyone know what the fix is? Parts available?

Thanks,

Stephen

Do a search here on the forum.
There's a lot of info on this problem. As I recall there are some capacitors that become weak and need to be replaced In the cruise brain.

Some folks reflow the solder in the control unit, there's also some vacuum stuff to check. And then there's the switch on the stalk itself. Reflowing the solder is a quick/easy fix if it is what the problem is.

I had my module repaired by a guy that advertised on ebay. You might want to check vacuum lines and make sure none are cracked but I've read that when it bleeds off speed it is normally the cruise module that is the problem.
My module was located in the "frunk" on the drivers side

I had a couple of marginal/bad cruise control modules repaired by the guy who offers the fix on ebay. He charged $80 each, however he just upped his price to $190. I was happy to spend the $80 but $190 is outreageous!
The two he fixed now work perfectly, so I decided to open them up to see what he had done. He had NOT replaced a single component on the board!! All that was done was he
removed the "varnish like" coating on the back of the circuit board and reflowed every
single solder joint on the back of the board.
I still have a couple more marginal modules in my inventory, and am going to try the
"remove sealer on the back of the board with solvent/paint remover and reflow all
the solder joints" trick like the Ebay guy did. Hopefully I can save the $190 per module that he now charges! I will update this post if successful or not. Wish me luck!

If all it does is bleeds off speed, you can forget all the trouble shooting stuff. The problem IS the module!!!

SWEET MOTHER! $190?? I didn't know what he did or how he did it but it worked for my car. I guess I wasn't really trying to endorse a person as much as just let the OP know there are options out there. There are other names of guys who do work on the modules in other CC threads.

Thanks for the heads up.

cruise
 

Thanks guys I will pursue suggestions. Anxious to hear about cleaning and solder flow works.

I reflowed mine and solved 95% of the problem. Instead of rapidly accelerating to the set speed and then dropping down 10 MPH and then accelerating back up again and again... now it only drops 2 MPH before it tries to regain speed. Still irritating, just not as. Technically 80% solved. Was going to send it in to the ebay guy for the final repair but not now. Will have to find another solution.

OK, here's the update. EUREKA!!! I took my original broken 1980 CC unit and decided to try to fix it. Used a 30Watt soldering iron with a very sharp point and used some very fine thread like solder. I used Acetone to remove the sealer on the back of the board. I used a one inch fine strand paint brush, continuly dipped the brush into the Acetone
and bathed the rear of the circuit board while standing up in a dish. The Acetone completely removed all of the sealer. I then proceeded to reflow EVERY solder joint on the back of the circuit board, adding a little extra solder to the joints that had a minimum of original solder. Reinstalled in my car, and VOILA, it now works flawlessly!
This unit had started to just lose speed slowly while cruising, then got worse and worse, till it wouldn't even engage at all! Now it runs like it did when new! Don't know if this is a fix for most units, but given the ones I had fixed by the Ebay guy that had NOTHING done other than reflowing the solder on the back, it's sure worth a try! Plus, just saved myself $190!!