Speedometer help needed

[95Viper]

Car: 95 RT/10, 2K miles
Symptom: Speedometer on rare occasions bounces all around from current speed to zero.
- Never does it when I first drive car. Has not done it this entire year.
- Appears to only do it after car has been driven for at least an hour and has been started and stopped. (This might not be 100% but I'll start keeping records)
- Hitting bumps seems to affect it once it has started but it doesn't make sense that it doesn't start right when I drive it if it was something like an electrical short.
Actions so far: Checked connection at trans. Replaced speed sensor. Checked wires over trans with no fraying. Added plastic wrap around wires going over trans toprevent future problems there. Checked connection at speedometer but this was difficult to get to so I'm not sure how well I did.

What is left? Electrical(I know nothing about electrical), bad speedometer? Where does the speed sensor wire go before it gets to the speedometer?

 

[Wild Bill]

I have found that if you can keep her between 125 and 170 you are to busy to notice the speedometer

Bill
(couldn't resist)

 

[Bandit3]

I believe there is a speed sensor on the transmission, check for faulty connection there. John

 

[95Viper]

Replaced speed sensor

 

[95Viper]

Any other help? Anyone in Michigan with electrical knowledge? I really don't want to go to the dealer on this, they worry me too much and I'm too far from Tator.

 

[Kurt 97 GTS]

Had a similar problem and after replacing the speed sensor I still had the same problem. I noticed that we the speedo was acting up, hitting the turn signal would correct the problem. Ended up being a loose ground wire causing the problem - check it out!!!

 

[95Viper]

Kurt, I'll try the turn signal as soon as it happens next. Dumb question but where is the ground wire? All I've noticed is the plug type connector at the speed sensor and the same type plug connector at the speedometer. Is there something in between that the wires go to? Thanks a lot because this is bugging the heck out of me, Craig

 

[Jeff Torrey]

I had a similar problem last year with my car. My question is; Do you have stock rear gears? Bought my car used, previous owner swaped out the rear gears. When you do that you need a calibration box for the speedometer. Turns out the calibration box went bad, had to be replaced.

 

[95Viper]

Yep stock gears...I guess I'm looking for that ground wire Kurt mentioned. Anyone know where to look?

 

[95Viper]

Wire guru's out there...the speedometer and turn signal share the same ground. Do you know where this is? Is it something you can see or is it wrapped in the wiring harness?

 

[FE 065]

Ask our MCVO VCA Zone director. Electrics are his specialty with DC.
(look under club officers at MCVO website)

 

[95Viper]

Thanks...I was in White Lake Saturday, my in-laws live there. Do you know anything about this DCSS Autocross Sunday at Great Lakes Crossing? Are you going ifit doesn't rain?