Car is an '88 S4 Auto. I recently started getting intermittent speedometer & odometer issues, and they happen at the same time. All other gauges are working correctly. A friendly love tap on the dash pod does not seem to change anything.
I recently did some tinkering in the spare tire well so the issue could be related as my understanding is there is a signal connector in there I may have bumped unintentionally. Does anyone have a good photo of what I need to look for if that might be the cause? I found some discussion in the archives but no pictures so I want to make sure I'm looking for the right thing.
There are two brown wires in the 6 pin connector. If you follow them away from the main loom, they will join together in a thin, black loom and go through that large grommet on the right side wall of the spare tire well.
Those are the speedo sender wires that go down to the speedo sender on the differential.
Extremely common to have "issues" right at the 6 pin connector...on either side of that white connector...or a problem inside, with the pins making a good contact. You can try contact cleaner/oil and see if that cures the problem. (Wurth makes a fantastic contact cleaner/oil.)
I generally need to make sure this gets fixed, completely, the first time....to avoid cars coming back for the same problem. I generally will cut the wires off, abandon the two wire connectors in the 6 pin connector, and install a Deutsch waterproof, gold contact male/female connector here.
I've never had to go back and fix this area, a second time, when using these super high quality connectors.