I am having these very annoying electrical problems and I am at a loss to figure out what it would be.
2001 sunfire 2.4

when I'm driving around, when I have my heater fan on (this morning it was 3 highest speed), all of my dash stops working, my speedometer, tach, temp and gas needles all go to the very bottom and my mileage indicator says error. I put the fan on speed 1 and everything came bakc working normally.
If I hit the brakes my speedometer and tach will freeze where they are, and when I release the brakes, they wil "jump" to where they are suppose to be. But if I hold my brakes for more than 5 seconds or so, then all of them(tach speed gas temp) stop working again, until I release the brakes, then they work fine.

I replaced the battery about 1 1/2 months ago(would'nt hold a charge).

it happens every now and again, then stops for a while, but now since yesterday its come back and its very annoying and I would like to get it fixed once and for all.

Any suggestions?

Thanks in advanced

sorry wrong spot, i'll repost on the maintenance forum