Mike C.

A few months ago I took out the brain and re-soldered all of the connections on the board. It worked well for a while. However, it gradually began to hiccup. At first a hesitation now & then, and gradually, refusal to operate once in a while, now it does nothing most of the time. It seems to have gotten worse with the cold weather although even when the interior heats up it won't necessarily work. The board has 3 can-like components which I believe are electrolytic capacitors. I recently was able to repair my clock by replacing the two electrolytics in it. Can anyone confirm that these devices are electrolytics on the cruise board? They are labeled 'Frako' and 10/63 (2 of them) and 22/48. They also show a + sign which is consistent with polarity found on electrolytics. Am I correct that the 10/63 means 10 uf, 63 volts? I figured it might be worth a try replacing these.

WolfeMacleod

All your Frako needs
http://www.frako.de/index2.html

Mike C.

Bump. There must be some electronics guys out there....

Rip It

same here, my cruise control is mostly inop now its cold.

StoogeMoe

Well, with values like 10uF and 22uF, they sound like capacitors. However the voltages are unusual (if they are voltages). I'm not familiar with Fraco compontents. Do you have pics?

Mike C.

Here's a pic. The 10 and 22 values don't have units. I'm guessing they are uF. I thought the voltages sounded a bit strange too. It is can-like and looks similar to the electrolytics I replaced in the clock (I don't think those were Fraco though).

jpk

They are likely electrolytic capacitors, as are the two light blue ones half cut off on the right side of your pic. The voltage rating is just an upper limit, kind of like the max pressure rating on the side wall of a tire. It doesn't mean that it has to operate at that voltage.

edit - the frako website list that they specialize in power capacitors. I'd say the likelyhood just went up.

Mike C.

Thanks very much JPK. Replacement caps should be cheap - worth a try...

hderr

So, how are you making out?
I've got one working and one non-working board that I'm working on :-)

I've got both apart, with the working one to compare, in the attempt to get the other to work. I've resoldered sections of the non-working board to get it to match the pin resistances in the working board. I'm hoping I got it, but too late to try it out this morning.

If you need any pin resistances for comparison, let me know.

hd

Mike C.

I'm about to chase down replacement caps for mine. Once I solder those in I'll see what happens.

Porsche-O-Phile

This is interesting. For the longest time the only solution to c/c related problems was "just resolder it" which doesn't seem to be all that great in terms of advice. Something like this (identifying actual components like capacitors that are prone to eventual failure) is far better. I hope it works out. I've got several dead ones sitting around I'd like to try to revive. . .

A lot of people just say "delete it". I personally hate this - I think the fact these cars had cruise control at all in the early 1980s is remarkable. . .

Mike C.

I really think the servo controlled cc is better than the common vacuum operated ones. Too bad it didn't have robust electronics to match... I have a long commute to work so cc is important to me.

I did solder in new caps but first test drive was negative. I wasn't able to get exact values for some of them and am not sure how important that might be. I'm going to mail order them to get exact values and try again.

There seem to be many other box-style caps on the board. I'm not sure if these type are prone to going bad with age.

hderr

Mike, I had hoped that my resolder job last night was going to work, and I would then suggest you try that again, seeing as it work for you before. I took the garage queen out for a run tonight and the resolder has NOT solved the problem. In response to Porshe-O-Phile, reason that resoldering is suggested is that it is an easy solution, sometimes, :-) > (and my 79 Firebird has cruise, never, ever a problem).
Testing components in a board is near impossible unless you put power to the board and have another powered board to compare. In regard to how important it is to have the same capacitor, my experience with capacitors is that they are like resistors, good to be the same, but close also works.

Is there any reason to believe that the capacitors on the board tend to go bad, other than your experience with the clock?
Hank

Mike C.

Hank, basically the electronics techs I've talked to at work think that the electrolytic capacitor is the component most likely to show aging effects. Apparently the dialelectric material can dry out - something that doesn't happen with ceramic, tantalum and other cap types. I imagine there are some knowledgeable people about such things on this list but I've yet to hear from them....

Mike C.

Update: I spent some time trouble shooting this past week and found that at least part of my problem was a bad cruise control stalk switch. Since I was getting no response at all from the cruise, I went back and did the pin out tests per the FSM. It turned out that the 'set' function was not getting 12V to the brain. I attempted to get the switch apart but could not do so without breaking it. I did find a small tab on the 'set' part of the switch guts that was broken off. Depending on how it broke, it might have caused some intermittent 'set' problems. So I pulled the relevant wires out of the cruise stalk and wired them up to a small switch and was able to get things working again. I was able to successfuly test the brain with the new caps so we'll see if this does infact fix any of the surging behavior (which I wouldn't expect to have anything to do with a bad 'set' switch).
Stay tuned....