I have a 97 A6 Avant that has an intermittent problem. The dash lights will go dim and flicker, the voltage gauge is erratic, and I can hear a clicking sound coming from the drivers side footwell (under dash) area. I've read alot on the forum about the hazard relay going bad, or possibly the turn signal switch - however this is a 97' and doesn't have the hazard relay built right in the hazard switch like all the examples explain. I know there are several relays in the drivers footwell - is there any way to test these circuits? It doesn't have this problem all the time so it is difficult to try replacing parts if it's currently OK! Any ideas? I don't want to be driving at night and lose my lights. I have replaced the alternator and the ignition switch. Thanks!

 

I would check my grounds. A loose ground wire will give you these symptoms. After that, I would check all possible electrical connections to make sure one is not loose, including and especially those on the alternator and ignition switch. Then I would start replacing (actually I would jumper out as a test, first, before actually buying anything) relays in the footwell. AS you said, its tough to diagnose an intermittent electrical problem.