For some reason my speedometer and tach have started bouncing around for no apparent reason. I can't feel or hear any difference in how the engine is running when it happens. The speedo will sudenly drop or gain like 7 mph almost instantly, then bounce back Same w. the tach. I couldn't tell if they both happeded at the same time. My volteage meter was also fluctuating. Think it might be sudden drops/surges in voltage? Any ideas? Oh, I had my gauges out this weekend, but it didn't start until today (3 days and ~200 miles ) Any thoughts? Loose connection?

 

Since you said you had the gages out I'd check for loose connections like you said. However, my gages acted the same way when my igntion switch went out.

 

I havent had my guages out but my voltage meter likes to go up and down. The only difference...my lights go with it!! Kinda like a standard when youre about to kill it but when its sitting at idle or when coming to a stop. I had my battery and my alternator checked and theyre operating properly, any ideas??

 

Check all of the grounds.

 

Sounds stupid but in my friends Trans Am, whenever he got on the gas or hit a bump, his gauges would all go haywire. He later found out it was the battery was loose and the positive terminal was making contact with the air conditioner. You can tell if it is by checking if the battery is loose and if there is a bunch of carbon on it where it was arching.

 

Never thought about it arching before...theres about a 3-4 inch space there though and everything is tight. But now i have something coming loose under my dash pad...if its not one thing its another!