:-[My speedometer is not working. It bounces up and down making it impossible to tell how fast I'm going. ( I can drive by the tac but I want it fixed)<br><br>Has anyone else had this problem? Any ideas on what it will cost to fix it? Thanks.

 

Don't know what truck you have, but you might wanna check the speed sensor in the rear diff.

 

How is the performance of the truck? Is it the same as it always has been or has it decreased a little? If so it might just be the speed sensor in the rear diff. just like emjay said.

 

I have a 1999 4x4 ram. The performance of the truck hasn't changed. The speedometer just bounces all over the place. Every once in a while, it will go back to working only to start bouncing back and forth again.

 

I have a vague recollection of a TSB having to do with the CCD bus connection to the instrument cluster failing due to a connector or wire problem. I can't recall the details, but you might want to research it.

 

&quot;I think I would start by doing the instrument cluster diagnostic check. Hold the trip/odometer button in while turning on the ignition key. It will go through the diagnostics and give you a code if there is something wrong. If that checks ok, then the sensor is the next step. However, if the problem is intermittent, you might want to do the diagnostic at a time when it's acting up.&quot;<br><br>Gary<br><br>Thank rattle_rattle for this. Not sure if it will work but its worth a try.

 

Thanks. I'll give it a try.

 

Your welcome, but I owe it all to rattle_rattle ;D

 

I had a similar problem, mine would drop off and then I would get a &quot;check engine&quot; and &quot;brake&quot; light. Occasionally the reading would return. Replaced the speed sensor on the rear diff. and took care of the problem. I got the part from the dealer and I believe it was under $40.00. Easy to replace.<br>Hope this helps

 

My brake light comes on too. I'm glad I'm not alone on this. I think I will replace the part. Thanks for the help.