How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site. Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask sprinkles08 Your Own Question
sprinkles08, ASE Certified Technician
Category: Jeep
Satisfied Customers: 22983
Experience:  Chrysler/Dodge/Jeep Master Certified, ASE Master and Advanced Certified, Trans and Hybrid Specialist
Type Your Jeep Question Here...
sprinkles08 is online now
A new question is answered every 9 seconds

2007 jeep commander 4.7 flex. Speedometer and tach bounce

Customer Question

2007 jeep commander 4.7 flex. Speedometer and tach bounce while driving. Replaced speed sensor but new cluster in still came problem. When in park the tach moves up and down. Please HELP!
Submitted: 1 year ago.
Category: Jeep
Expert:  sprinkles08 replied 1 year ago.

Hello and welcome to JustAnswer!

I would first suspect the instrument cluster if it's affecting both the tach and speedometer but if it has been replaced with a remanufactured unit and the problem is unchanged then you should be able to rule out the cluster.

I've seen failing alternators induce electrical noise that would cause issues like you're having, especially the speedometer moving on it's own while not moving. Can you try unplugging the alternator field connector when the problem is happening and see if it goes away?

Customer: replied 1 year ago.
No alternator is fine.
Expert:  sprinkles08 replied 1 year ago.

How did you determine that?