Dash and headlights blink... any ideas?

A couple weeks ago the Check Engine Light came on, and then this and the other dash light sbegan to blink everynow and then. It will dim, back, dim, back for about a minute then it will stop for a few minutes. Then dim, back, dim, back... for a couple more minutes then it stops again.

Had the check engine light testedm it came back as the front O2 sensor, but he did not recommend changing out that ($270) part since he doubted it would cause the blinking problem.

Any ideas or suggestions? The alternator, battery, and both O2 sensors tested out just fine in diagnostics.

Thank you!

sounds like a poor ground somehwere

I thought about that too. I removed the groundwire in the engine compartment and brushed it off really well, no change. I checked the battery terminals and tested the battery, also fine.

Anywhere else you can think that I might check?

How about checking the alternator - or the tension pulley for the Serp Belt.