Chrysler Repair: Speedometer/odometer wont work: 91 New Yorker, chrysler new yorker, bump in the road

Question
QUESTION: Hi Roland.  Here's another brain teaser for you.  My 1991 Chrysler New Yorker's speedo/odom quit.  All the other guages are fine.  It didn't pull a trouble code and is not in limp mode as with some of the later years when the speedo stops working.  I replaced the distance sensor on the rear of the transmission to no avail.  Next suggestion was to replace the cluster which I did with a used same year, same model.  Still no dice.  I've checked these White/Orange wires:distance sensor to PCM# 47. Distance sensor to red plug cluster position "C" They all showed good readings:  0000  continuity.  Also the Black/Dark Blue from the sensor to PCM position 4 was good.  Thinking it may be the connectors plug to the sensor I made two wire leads to join the sensor and supply plug.(When the speedo wouldn't work sometimes hitting a bump in the road would spring it to life making me think it was a loose connection hence I tried the wire leads to make a positive connection) Also the cluster show battery voltage at the pins feeding the speedo as well as continuity from the sensor to speedo pin.  Any other ideas?  Thanks for any help.  Ed

ANSWER: Hi Ed,
It appears that you have covered all things electrical. I would therefore suggest that you put your ohmmeter across the distance sensor's terminals and jack up the right front wheel and try turning the wheel by hand. See if you get 8 pulses of the resistance reading per revolution of the wheel or not. Perhaps there is a problem in the gear that drives the distance sensor's gear. If you get the pulsing I can imagine why you don't get any responce at the cluster, given what you have told me you have done.
Please let me know if you find something interesting.
Roland

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QUESTION: Roland,
I originally checked the old sensor as you suggested and since I couldn't get a reasonable reading, I replaced it.  I rechecked the new sensor and did get 8 pulses per revolution.  I think I may have gotten the same result with the original sensor if a turned the elevated wheel more slowly as I did in the second test.  If electrical seems OK I'm wondering if I maybe getting a false reading on a wire line check so I may try bypassing the "good" lines with a temporary line and see if I get a better(for me) result.  Even if the speedo just moves for a second or two it will help me concentrate on particular area.  I know I'm grasping for any idea. Ed

Answer
Hi Ed,
It is such a straight forward shot from the sensor to the cluster and a ground lead from the PCM (or prabably any ground would do) why not try that. I wouldn't be surprised though that it may be in the cluster at the board socket interface, or on the board itself. I can't give you any other suggestions unfortunately. If you get pulses at the cluster C pin and you have voltage and a ground on the other specific pins, and you don't get any action then there has to be a break between the socket and speedo/odo or the used speedo/odo is bad.
Roland