Blue944

I had good luck fixing both of my cruise brains.

My 944 came with cruise that did not work, so I got a "working" brain from ebay. When I installed it, it would do the accelerate till explode thing ( I think the car just likes to go fast anyway). So I started looking for solutions and saw the post that suggested resoldering the contacts.

I broke the brain apart and took the circuit board out. It does not appear to have cracked solder joints, but I know from other experiences that you can not tell a bad electrical connection by looking at it. I got out my handy soldering Iron and resoldered all of the connections (about 200). It really did not take too long. I popped it back in the 944 and it works perfectly!

I cracked the 2nd brain, resoldered it, and it works perfectly too. Now I have 2 working brains.

If you want to do this, I would suggest a high quality soldering iron, and a steady hand. Just heat each connection untill the solder melts, and let up. I have no idea which connections go bad, so just do them all.

I also don't need the 2nd brain anymore, so if someone wants it, let me know. I will sell it for $50, and I guarantee it works.

-Mike

bron964

my cruise control has a mind of it's own sometimes. i think i'll be trying the steady hand resoldering soon.

thanks for the info!!

Dano_944

Mike - my cruise control just started acting up... after I put in the Performance Products quick throttle cam...... It tends to decelerate and excelerate abbruptly.

What year is your car, and is it a 944 or 951? I may be interested in the unit.

Thanks!

Dano <img src="graemlins/beerchug.gif" border="0" alt="[cheers]" />

Peckster

I just installed used control stalks from ebay on my 951, and quess what? Same problem! I guess that was the PO's way of fixing the problem--he just broke off the stalk.

It just kept accelerating when I tried it today. I thought maybe that was Porsche's idea of a good cruise control...accelerate to max speed and hold it there, heh heh.

Anyway, if Dano isn't interested, I am, and I will even pay in $US. If not, I'm breaking out the soldering iron. So, what do you mean by a high-quality iron, one with a fine tip and not too much voltage? I guess my Weller gun won't cut it.

Thanks, jp

Peckster

Blue944

My car is a 89 944na. If either of you want the brain, please let me know.

As for the soldering iron, I would suggest a soldering pencil, and a fine tip. I got mine at radio shack. Keep the tip tinned with electronic grade soler at all times, it will tend to suck the solder off the board otherwise.

- Mike

Bri Bro

Did you look to see if you cruise control switch is sticking after you set it? With the switch stuck in the accelerate position, the cruise control computer is simply doing what it is told.

Peckster

It didn't seem to be sticking but I'll check that too. Maybe just pull it back a little after setting it I guess. Thanks, jp

Bri Bro

My advice is to check it with a DVM on the cruise control unit plug. There is a good checkout procedure in the manual (27-23), did you go through this? Another thought, if the speedometer signal was not correct, the control unit would try and accelerate up to speed. This signal is also on the control unit plug. A bad solder joint as described above could also make the speedo signal incorrect and away you go.

Sound like you don't have a soldering iron, might want to take the control unit down to your local TV repair shop and ask them to resolder the connector joints. Over half of the repairs to TV are cold solder joints so these guys are experts in resoldering them.

Stefan

<img src="graemlins/bigok.gif" border="0" alt="[thumbsup]" />

Just did the resoldering trick. Worked like a charm. I was even sceptical because the contacts looked to be in great shape before I started.

Thanks for the tip!

(I used a 15Watt pencil iron from Radio shack for $10 and silver rosin core solder to fix up any contacts that needed solder.)

Peckster

Mine worked fine for a while when the car and weather is warm, but is now back to the same problem on cold mornings. What did you solder, Stefan? The brain connections?

kevin Dubois

i'm about to start the fix, but giving it a proir inspection i noticed it appears as if i am actually missing a resistor. holding the board so that you are facing the resistors, with the wire connections point away from you (or up). it is located in the left hand side, second column in about 4/10th's of the way down. there is a "13" printed in green ink where the resistor would be. if you have any idea of what i'm talking about please let me know and i guess i will start soddering now=) (i guess i'm asking if your board has two empty holes through the board in that area)

bpp944

1. Laptop in left rear corner of desk.
2. Control until sitting in front of me.
3. Soldering iron in the right rear corner of desk.
4. Labatt Blue Light in right front of desk.

Time to play....

bpp944

I'm 1/4 the way there. wow, steady hands are needed. I guess I'll have to set the beer aside for a while.

Lizard944

I did the resolder a few days ago and holy #%$@ it worked! <img src="graemlins/bigok.gif" border="0" alt="[thumbsup]" /> About two years ago, I made an attempt to fix the IC board. I work in Ophthalmology, and we have some pretty high powered microscopes. I took the board in and cranked up the magnification, till each solder bead looked like it was the size of a Hershey's kiss. Couldn't find any bad looking welds, but saw a few that were suspicious. Resoldered about 20 or so, but it didn't work. Set it aside and put it on the "I'll get to it later" list. Fast forward two years.. Got tired of going on road trips without CC, ordered one from Ebay, but seller crapped out on the deal (blessing in disguise).
Saw recent thread, and thought I'd try it again, this time doing all of the welds. Popped it in, then went to the highway. Got up the nerve to turn it on and then got a surge like it was going to full throttle again, then it leveled out. Needless to say I was happy as a "Mo Fo" <img src="graemlins/jumper.gif" border="0" alt="[jumper]" />

Lizard