2001 monte carlo Has anyone found the fix for all the electrical problems (radio/a/c/turn signals,temp guage,hard trans shifting all intermittent.pull over shut off engine restart most things start to work again. cooling fans run at all times. bcm replaced by dealer for $500 didn’t fix it. no doubt a computer problem but has gm made an upgrade or a patch for these cars?
I see a capable independent mechanic, with electrical knowledge and skills, in your future. The dealer isn’t the one.
Your problems seem to be with the electrical power supply–starting at the battery and continuing to the ignition switch, and on.