aftermarket cruise control

[Surfalia]

The PO of my syncro installed cruise but when I got the van it wasn't operating. I have checked all the wires and found everything seems to be working but found the pickup/sensor that I believe would normally be located as close to the driveshaft with the magnet type thing attached, but the wired sensor is not even close to the driveshaft and is actually closer to one of the CV shafts but no magnet is attatched. I have installed an aftermarket CC on an Isuzu Rodeo back in the day and remember some of the install(long ago). Ironically I did find the magnet that I remember would be on the driveshaft in the ashtray on the dash in my van. To be sure I just wonder if anyone has installed an aftermarket CC on their van and did they put the little magnet thingie on the driveshaft or a CV shaft?
Thanks

[rs4-380]

i installed a audiovox unit on a manual transmission. Because it can run off the tach signal it does not need a speed sensor.
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Dave
87 EJ25 Syncro GL

[Volksaholic]

I don't know if this helps at all, but my Vanagon came to me with a Dana vacuum unit installed that hasn't worked since the get go. I guess Dana was purchased by (or maybe built by) Rostra. Anyway, mine has a sensor next to the CV boot... it looks like a magnet probably bolted down underneath one or two of the CV bolts. They were loose when I got the van and there was no magnet there.

In reality I don't think it matters where the magnet is installed... on the axle or CV. I suspect they're only measuring wheel rotations and it wouldn't matter where you picked that up. The cruise has to be calibrated somewhere to the tire diameter to calculate the speed I'm guessing (I'm guessing about all this.. I've never done any cruise control troubleshooting). I've though about mounting a magnet down there but I'm more inclined to replace the unit with a newer Rostra electric setup rather than trying to fix the vacuum unit without any documentation.

EDIT: On second thought the cruise control probably doesn't need to know how fast your going. If your speedometer if reading 70 mph and you set it, it "learns" how many wheel rotations you've locked in on and doesn't care what the speedometer reads. Again, whether it got those rotations from the axle or the CV wouldn't matter.
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1988 Wolfsburg Edition, 2001 Subaru EJ251

[Surfalia]

I like the tach connection idea but I guess since the sensor is already under the car I'll try that way. I would try the tach connection but the tach just crapped out this past week. It went intermittent and now nothing from the tach. I thought maybe the plug under the dash might be the cause but the fuel guage and temp guage are working so I guess that may not be the cause unless the foil is fried where the tack curcuit is. Where does the tach get the signal from at the engine. Is it one of the wires on the coil?

[Dogpilot]

I have the Rostra unit. Originally, I had the magnets on the CV. I put four secured with sealant then strapped around the circumference with a tie wrap. It worked, but not as well as when I scored a VSS for the speedo head. It is a common part, and any of the Audis or VW of similar vintage may have one like it. I got mine from an Audi Quattro. With minor mods it fit perfectly, and has been humming along in there for a couple of years now.

Tach gets its signal from the coil.

Get the schematic from my public folder:
Vanagon Wiring Diagram.pdf
http://homepage.mac.com/WebObjects/FileSharing.woa...mp;lang=en
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Geology with a Syncro rocks!
86 Syncro Westy AKA "The Bughunter"
98 Disco I
08 Range Rover SC
08 VW Rabbit S
1951 O-1G