I just bought a 1994 Toyota Camry had to use own battery and buy a new alternator fuse. Now everything is running ok but the stereo won't work

Do you have battery power at the alternator post ?
Could be an open fuse.

It is strange ! But anyway, check the wiring from battery to alternator and the earthing wiring. Have you used a new alternator or not . If the alternator is a second hand one have you checked it if is working before fitted on the car ?

Don't just test fuses, but probe with multi meter for power.

Alternate check is to run fused wired direct from battery and see how that works

You do not state whether the starter actually cranks the engine or not. If it does so strongly, but the engine won't fire, then this stuff below doesn't apply.

There are several other things which may be the cause. Alternators are usually quite reliable, so check the alternator drive belt first to see it is not loose or broken. Is your charging warning light on the dash lit up? That should come on if the alternator is not charging.

The failure to start could also be either an old battery that will no longer hold a charge, or, the battery is OK but yes, the alternator is not charging it properly, or, the starter motor has a fault, or, in an auto, the start switch on the transmission has failed.

There is a test, but it needs the engine to be running. If you can get it started somehow, turn the headlights on high beam, have someone watch them, and rev the engine moderately.

If the headlights look dim at idle, and flare up brightly when the engine is revved, the battery is weak and the alternator is OK.

If they are dim all the time, it is probably the alternator at fault, or, the alternator drive belt is loose or broken.

If the lights are bright all the time when doing this test, it is probably the starter motor solenoid contacts. These do wear out in a Camry, and can fail only sometimes when worn down.

Check the 30 amp power fuse in the fuse panel on the inside at the left lower dash.

I think the ECU, alternator, igniter, stereo and RPM gauge at least are damaged.

this is an electrical issue. Here is a link to a full description of this vehicles electrical system>>> http://www.turboninjas.com/camry/be.pdf

please rate...thanks

As you are finding out ....this is how you kill a car. You need fuel, spark, compression, and air to run an engine. Look for spark and fuel items to be working. A computer controls much of the spark part. They canbe sensitve electrically. If you are cranking ..starter sounds ok. Alt. will act up after you get started. concentrate on spark and spark control. Fuel and fuel control. This is what you need to start.

With the engine running disconnect the battery cable. If the engine quits that tells you that the alternator is not working. If the engine continues to run then the alternator is good.