I changed the battery on my 2005 toyota corolla today and switched the positive and neg then tried to start it an realized my mistake. i saw 4 blown fuses inlcuding the alt fuse which i replaced and still will not start. any suggestions??? it wont start. the lights,radio a/c work but just wont start help

is the battery good no bad cells?also check your cables both positive and neg cable

It could be a very expensive mistake. Easy to destroy certain parts of the alternator that way. But even with a bad alternator, it could still start and run-until it runs the battery down. It is cranking over, isn't it?
And more worrisome is the health of your computers on the car. Begin by testing the ignition system-that is controlled by the computer. You need to check for spark on the spark plug wires. If you have a blue, snapping spark, the ignition system is probably good. If no spark, you had better have a person with a digital volt- ohm meter and a wiring diagram of the car examine it, and check the pcm.
I'm not sure about that alternator fuse. Some cars even have an in line fuse, and some still use fusible links as protection between the alternator and the battery. Sorry I can't help you more. Check for spark.

Same thing happened to me. Turned out to be a blown Alt fuse (under the hood behind the battery, you'll have to unbolt the whole fuse box though. That fuse is bolted in from underneath) and a blown am2 fuse (look underneath the dash of the driver side from inside the car). I switched those out and the car started right up

It is a pretty good bet that you fried a number of components, however there is more than one fuse block. Look under the dash. There is also a box that has relays and circuit breakers. Test these too.

Check battery cables for corrosion and good connection.
Try to boost it with jump starter.
Try to tap on starter while attempt to start.
To me sounds like a bad starter.

1. I tried to find a
   Toyota Corolla Wiring Diagram 1998 |
   If you go to your library you can look for free. Just not sure of location of of neutral safety switch for your year of car. In the back of motor manual is wire diagrams you will find switch there. Also GEO Prism is the same car.
   
2. The last time I worked on a Prism it was a 1997 I found a bad wire connection at the shifter. Took 20 minutes to do repair and no parts.
   
3. So I would check the switch in your console. Sometime they stick or a wire comes loose. Sometimes a little WD-40 shot to the switch helps.
   

CHECK HEAD LIGHT CIRCUIT BREAKER AND DRL RELAY OR RELAY.IF ALL IS GOOD.A BAD DIMMER SWITCH OR GROUND WIRE PROBLEMS.

First, have the new battery tested & fully recharged.

You may find you problem at any point along the way but here is the proper procedure.

Now, you will need a digital voltmeter to really perform this test properly and be prepared to have a blown fuse or two, as you will be testing the system by removing and replacing them.

Install the freshly charged battery, making sure the terminals are clean and well protected with vaseline or grease. Install the Neg (-) connection last when installing the battery, remove it first when taking the batt. out. Check your negative connections.

Before connecting the Neg. cable, take a reading with the voltmeter to see what the current voltage is, it should remain fairly constant with a good strong battery when disconnected well over 12.6 volts.

Connect the Neg cable and connect the multimeter again, you should now see it start to drop, depending on what is draining the battery, fast or slow. If you note this drain is heavy, remove the neg cable again.

Make sure all things are turned off, brake lights are off when pedal isn't being pushed, no interior or trunk lights left on.

Next, start the car, the multimeter voltage reading should increase or hold steady, no drain or the alternator is not charging and could actually be draining the battery. Check belts and wiring harness plug-in.

If you haven't found your problem, make note of the fuse positions and remove them all. Connect the battery Neg cable and test for drain again. If the car isn't draining anymore, install a fuse at a time until you find the one causing the drain of voltage & then you'll have to trouble shoot that system.

There is a tool that fits over the wiring that will indicate current usage without removing the fuses and such, it's available at most parts stores but until you have one this is the way to find the problem. Isolate it.

good luck

check for the red fuses those are usually power fuses check all red fuses make sure they are not burned

I believe the reason the lights would still work is due to the fact a light bulb doesn't discriminate about polarity. It would be fair to say you have fried relays in your car. These should be located in something that looks like a fuse box in your engine bay. Some may also be in your fusebox. Hope this helps and good luck.