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Cruise control testing on 1988 s4 auto

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Old 11-16-2016, 06:36 PM
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John Tonkin
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Default Cruise control testing on 1988 s4 auto

I have not had cruise control since I bought the car 2 months ago. I have tested cc module plug as per manual ,all power and earths are correct on the pins and switch on and off with the stalk as they should. The ohms readings are not as manual at the plug or under the wing operating servo plug and I dont know what thats telling me! The module has been tested for dry joints and resoldered. Any suggestions?
Old 11-16-2016, 06:58 PM
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ROG100
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The 88+ module rarely fails but it may be worth trying another one.
Are you getting a signal from the cruise switch on the steering wheel?
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Old 11-16-2016, 07:19 PM
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John Tonkin
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Control stalk is operating fine
Old 11-16-2016, 09:05 PM
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My 88's cruise didn't work when I bought it. Chased down all the other electrical control stuff/tempostat and it was found to be ok. All the vacuum lines were replaced.

The mechanical vacuum/servo unit (same one as in 944) attached to the throttle linkage was found to be stuck/unmovable and therefore inoperative. A new one went in and it works great. I don't have the part number in front of me, but that was what was broken in my case. Hope this helps.



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