gauge needles bouncing
 

I was curious since I have not noticed this before, but I just noticed the needles on my gauges bouncing while driving on these rough Louisiana roads. The gauges that seem to be bouncing are the Tach,the druck pressure gauge and the temp needle.

Is this normal that the needles are bouncing or is it a sign that I have either electrical problems or gauges going bad.

You may have a relay that's going south.

I had something similiar. First it was the pressure and temp. Then the RPM started going all over the place. Most on the board suggested it was the voltage regulator. I pulled the alternator and noticed it was original (has the built in voltage regulator) and decided to replace the whole thing with a rebuilt.

Of course, I had a while I was at it moment and started working some other electrical problems.

I'll be installing the rebuilt alternator this week so I hope that fixes all my problems.

Michael

check the grounds - then the relay, then Vreg, alt., etc.; bad gauges are the least likely explanation...

I should add, I checked with a voltmeter to see the voltage spike.

Randy brings up an excellent point on the progression of checks. He's the one that helped me diagnose my issue.

One thing, how do you check a relay?

On my relay, I took it apart and looked for burns or wear on the contacts. I also posted some pics with questions. Then as I was trying to get it back in the poorly located hiding place the Germans found for it... it crushed. So I bought a new one...

That's how I "checked" mine....

I'll do all of the following checks Randy suggests tomorrow, but just out of curiousity....my gauges only do this while traveling on rough roads..I just took her for another drive and noticed that the gauges were acting normally, only when I hit rough road does it do this, so I am thinking maybe a bad connection somewhere. But I'll check tomorrow

Check your battery terminals too. Unscrew them, clean them with a wire brush, and rescrew them. Very often, a ohmic drop there will cause these symptoms.

Aurel