I'm experiencing a backfeed problem on my street/strip 71 GTO. Whenever I use my turn signals the needle on my tach starts jumping (an Autometer 3904 w/ shiftlite). The only change I have made to the electrcal system is installing an H.E.I. distributor. Where do I begin to look?

I'm experiencing a backfeed problem on my street/strip 71 GTO. Whenever I use my turn signals the needle on my tach starts jumping (an Autometer 3904 w/ shiftlite). The only change I have made to the electrcal system is installing an H.E.I. distributor. Where do I begin to look?

Most likely the problem is a weak battery connection to the instrument panel area. The xtra current used by the HEI in your ignition circuit plus the current drawn by your directionals is causing a voltage drop in your battery feed harness. As a result your tach does not get enough voltage to work correctly.

Look for a bad/weak fusible link or a corroded fuse boxignition switch terminal.

Regards, George