Location of grounding strap 2004 sunfire?

Sounds like the connection on the back side of the instrument panel may have come loose.

Sounds like a loose connection somewhere.. Check your battery connections, (clean dry and tight) check your ground connections, body and engine ground, (clean rust free & tight) check the wires ging to the alternator, have someonE watch the light while you gently wiggle the wires at the alternator, while running.. WATCH OUT - MOVING PARTS, BELT CAN GRAB LOOSE CLOTHES TIES OR LONG HAIR.
Good luck

You or someone will have to figure out why your new alternator is doing absolutely nothing. Not only is it not putting out enough power to run all the car's electrical systems, it is also not charging the battery, so you could start it next time off the battery and not have to get it jumped. With it not working, the car has to use battery power to run everything, and when you use lights, or radio, or any accessory, the battery runs down even quicker.
One reason alternators don't work is loose or poor connections between the battery and alternator. You could remove your battery cables (check them, if they look old or worn badly, replace) from the battery (negative first) and clean the cable ends and the battery posts till the metal is shiny clean. Do the same for the negative cable to frame ground point. Then check the big cable end on the starter, make sure it is tight. Put the cables back on-positive first, negative last, then move to the alternator and check the connections there for a clean tight connection. A couple of other ground points you could check is the engine to frame ground-somewhere on the engine is a ground strap bolted to engine metal and the other end will ground on the car frame or on the firewall in back of engine. If this ground is lost, strange electrical problems may result. One more ground: often the engine and computer wiring harness will have a ground wire coming out of the harness-a short wire-and may be grounded around the top of engine-many cars do have this visible ground, so check for it and check if a good ground.
If you do all this, and still no help, cheeck all your fuses in the under hood fuse block-sometimes there is an alternator fuse there, a big maxi-fuse. Check if good, check all fuses. If no help, you likely need a mechanic or shop to figure it out. Good luck. Hope you find it.

diodes in alternator are leaking (back feed), more when hot. needs alternator or fan belt loose..

It sounds like the alternator is going bad. I reccommend pulling the alternator and having it checked out, most auto stores do this as a free service. There could also be another problem on the rpm thing but I would start with alternator and inspect all other pulleys that the belt rides with. Good luck.

First Check battery to motor and battery to body ground for corossion. Also check motor to body ground strap. Lack of good ground can cause all kinds of electrical problems. Also check altenator belt for slipping. If grounds are ok and belt is good have alternator and battery checked.

Check battery to motor and battery to body ground bolts for corossion, also check motor to body ground strap for corossion. Bad ground can cause all kinds of electrical gremlins

Nope , voltage regulator is inside alternator.
Does your charge light come on , if not , I suspect a broken ground wire or strap at the alternator.
No ground = no charge and no warning light.

Check your battery cable connections on the battery, starter, and ground. Might be dirty loose or damaged.

Look for a bad ground to the chassey, likely by the battery, starter or transmission. Clean the ground straps by removing the bolts to the body, then wire brush the area before reconnecting. Spray with WD-40 to inhibit future rust. Also, check voltage by the alternator to see if it is 14 volts DC when running. It should be around that by the battery as well. The on board computers and electronics are very sensitive to low voltage, flagging lots of problems when the alternator is failing, or battery is old or failing and lastly if the chassey isn't grounded well.