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Old 04-11-2007, 05:01 PM   #11
bmartin9122
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Join Date: Jan 2006
Location: Texas Coastal Bend
Posts: 169
Re: cruise control question

Quote:
Originally Posted by Zilverado View Post
Just curious - what kind of "erratic behaviour" you are experiencing. My cruise works fairly well, except for a slight (but pretty well constant) fluctuation in speed. Not enough to notice on the tach or speedo, but enough to feel it.

What/where is the "transducer"?
The erratic behaviour is similar to your experience, but more extreme.

Once the speed is set, the truck will surge and coast on flat (0% grade) roads randomly. Since I have already replaced the brake light switch, I am attributing this undesirable performance to worn-out vacuum diaphrams or faulty electronics in the transducer.

The transducer is the primitive brain controlling your speed. It is located on the wheel well near the firewall on the driver's side. The speedometer cable enters and leaves it, as well as, several vacuum lines, and one 2- or 3-wire harness. It is a complex little beast.
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