Cruise Control Fix

[ClickClickBoom]

Hello,
I am in the process of either fixing or removing systems. After following the Factory Maintenance Manual troubleshooting matrix for the Cruise Control system I decided that the brain box was at fault. I sourced one from a fellow Pelicanite and plugged it in, cruising in style! I opened the old brain and was poking around with a magnifying glass and found a capacitor that had an obvious leak and bulge, bingo!
Went down to the local electronics store with the board and said "I need 2 of them things that look broke" and after exchanging 2 of my hard earned dollars I went home. I broke out my pencil soldering iron from the '70s and some solder from the same era, a slightly newer solder sucker and removed the offending caps, soldered the new ones in and stuck it into the car, worked like a charm!
Flicks:
The installed thingys,


The caps go where the circles are


The broke one has the scab crud on the bottom


The $1.00 package, 47mfd/16v, I see a bunch of others with similar types of numbers, but they don't look bad so why fix what ain't broke!


If I (caveman) can fix one of these things, your average spongehead can too!

[86 911 Targa]

Originally Posted by ClickClickBoom

Hello,
I am in the process of either fixing or removing systems. After following the Factory Maintenance Manual troubleshooting matrix for the Cruise Control system I decided that the brain box was at fault. I sourced one from a fellow Pelicanite and plugged it in, cruising in style! I opened the old brain and was poking around with a magnifying glass and found a capacitor that had an obvious leak and bulge, bingo!
Went down to the local electronics store with the board and said "I need 2 of them things that look broke" and after exchanging 2 of my hard earned dollars I went home. I broke out my pencil soldering iron from the '70s and some solder from the same era, a slightly newer solder sucker and removed the offending caps, soldered the new ones in and stuck it into the car, worked like a charm!
Flicks:
The installed thingys,


The caps go where the circles are


The broke one has the scab crud on the bottom


The $1.00 package, 47mfd/16v, I see a bunch of others with similar types of numbers, but they don't look bad so why fix what ain't broke!


If I (caveman) can fix one of these things, your average spongehead can too!

Solder joints & caps are always the usual suspects.

Good for you, as many P-CAR guys spend $$$$$ for the same fix you found.

Ask me how I know.....

Gerry

[ClickClickBoom]

'nuther question for one of the solder heads. The board looked like it was dipped into polyurethane to seal and protect it, what would the correct material be to reprotect the board, and is it necessary?
Thanks
Eric
PS For anyone who might care, the black stripe indicates the neg side of the cap, the other side of the circuit board has little + where the positive leg goes.

[DRACO A5OG]

Nice Work Brother

Mine tends to drop in speed after I set it about 5-7 MPH, could it be the capacitors?

[ClickClickBoom]

Originally Posted by DRACO A5OG

Nice Work Brother

Mine tends to drop in speed after I set it about 5-7 MPH, could it be the capacitors?

If it holds that speed over time I would venture a guess that you have a vacuum leak somewhere. I had read on the forums here that speed bleed was indicative of capacitor weakness. My unit was dead, as a doornail and now works just fine, very slight oscillations as the throttle moves to maintain speed. I had a Honda Passport that when the cruise control was set would drop 7-8 MPH and hold that for ever, replaced the servo and it holds the set speed exactly. So I bet it would be the servo, but that is just one cavemans opinion based on the information gleaned from this forum.

[JAR0023]

Nice work. Thanks for posting photos.

I'm in the same boat with my '86. Been through the Bentley tests and all point to the CC "brain". I was going to send it off and have it rebuilt but after seeing this with the simple cap replacement I think I'll dive in. I fixed my clock and a Samsung LCD TV by replacing caps no reason not to try on the CC. -J