Why does your battery light come on the dash and all instruments go off but everything else still works fine if you rev it above 1500 rpm they work again?

When the battery light comes on and all the instruments go off, it's usually because the alternator is not charging the battery properly. This can be caused by a number of things, such as a loose or broken belt, a faulty alternator, or a bad connection.

When you rev the engine above 1500 rpm, the alternator spins faster and is able to generate enough electricity to power the instruments. However, this is not a long-term solution, and you should have the alternator checked out as soon as possible.

Here are some of the things that can cause the alternator to not charge the battery properly:

* Loose or broken belt: The alternator is driven by a belt that runs from the engine to the alternator. If the belt is loose or broken, the alternator will not be able to spin fast enough to generate electricity.

* Faulty alternator: The alternator itself may be faulty. This can be caused by a number of things, such as a worn-out bearing, a bad diode, or a short circuit.

* Bad connection: The alternator is connected to the battery by a cable. If the cable is loose or damaged, the alternator will not be able to send electricity to the battery.

If you're not sure what's causing the alternator to not charge the battery properly, you should take your car to a mechanic. They will be able to diagnose the problem and fix it.