Ignition Short Problem

[sharpcadd]

I have a '92 MX3 w/ a 1.8L BPT swap. I drove the car to work, and when I get in it to go home, I turn the key, and get nothing but a buzzing noise from a small box right in front of the computer. The lights dim down to nothing. If I hold the key in the start position for a couple seconds, again, nothing but a faint buzzing happening, let the ignition go and feel the + batt terminal, it is very warm. Sounds to me like a short, but where is it? None of the lights work properly just turning them on w/ out the key in start position. I unplugged the small box in front of the computer, and the buzzing comes from under the dash just to the left of the steering column and above the fuse box.

anybody know what is going on?

[Whisper]

Car's CPU is left of the steering column behind and above the fuse box. Is that where the buzzing is coming from? Check your fuses, if you've blown one, that might point you in the direction of the problem.

[sharpcadd]

I think I found the problem...

I've heard stories about how batteries can fail very suddenly. It's 11:00pm now so there's no getting a new battery tonight to test my theory, but I jumped the car, and everything started acting normal again. Once I had it running for a while, I disconnected the jumper cables, and turning on the headlights killed the car. And then once the car was off, the headlights would not turn on (xenon headlights from an RX8 so they won't turn on at all if there are not enough amps). So I'm hoping that the battery just had a sudden failure, and popping in a new one will solve this weird-a__ problem.

[OldMan]

It could be your battery is completely shot, but you need to have the charging system checked. If the car will start by boosting it, once it is running a meter will tell you if the alternator is working. If you can charge your battery up with a charger it can be load tested to find out if it is a bad battery, but the battery must be fully charged to get an accurate reading. The reason I say that your battery must be fully charged is that if it is not it will fail the load test. Most testers that can do the battery load test will also show whether or not your alternator is working. It should show a min of 12.6 volts, if I remember correctly, to a maximum of 14.2 volts when the car is running.

It is possible that your battery will charge up but will fail a load test, this indicates a bad cell, then you will definitely need a battery. How ever if you have fully charged the battery and it passes the load test , the battery is fine. As I said you must make sure the battery is fully charged. Many places will not tell you this and sell you a battery that you do not actually need. If the battery is good but the alternator is bad your battery may last a day or two depending on how much your lights and accessories are used.

One word of caution. Charge the battery on a battery charger. If your battery is really low or is by chance defective it can fry your alternator by over working it.

I hope this helps. Sorry for such a long post but I have seen people ripped off by being sold a battery when they really needed an alternator.

OldMan

[Whisper]

Could it be that something else shorted out the battery? If your battery is busted, I hope the new one you put in doesn't get busted as well because of the problem elsewhere.

[sharpcadd]

Turns out it was just the battery. Replaced the batt, and all the problems went away. Alternator works great, and all the systems came back on with the new one. Sometimes they just peter out.

[maryus]

i that moment when it didnt start you had at least the lights on the dashboard ? it happened the same to me now, when i turn to start it makes a sound you barely hear but the clock and radio goes off, and i have all the leds on my dashboard on . it happened the same to you?