Okay, to start, my car has 126,000 miles on it. There has been no real work on the motor, just normal sutff (plugs, wires, coils...) Here's the problem.....

All of the sudden, my speedo and tach will fluctuate abnormally if I have the A/C on, or the manual fan switch on, or a combo of that. It is as though there is a power problem and the computer is getting too many volts/amps. If I am sitting at a red light, and have the A/C going, then sitting still my speedo reads around20-30 mph and the tach goes up to around 3000 rpms. I can rev the engine and make both needles climb, but they are not sinchronized (i.e. the speedo does not rise in accordance to what the tach says, visa versa)

Can anyone please give me a solution??? There is no SES light, otherwise I would use my scanner on it. Let me know please!!!

 

Sounds like your alternator is going out. If it hasn't been changed yet then you're lucky... Mine went out at 20K miles.

 

I had some strange power problems caused by a bad battery Jeremy. Might check that out, yo.

 

Jeremy,

I had a problem like that once...battery wasn't strapped down good and when I accelerated the battery would move and cause a short that would cause similar problems....it would also do the same thing at idle if the car shook kinda bad...

check alternator like BLoodztone suggested...

check your grounds aswell and make sure none are loose..

later,
Rick