Hi -
I'm trying to work out if my alternator is dead. I have an 1997 899 Cinquecento SX.
First of all, when I turn the key to acc. the battery warning light doesn't come on at all. It never has, and I assumed this was just the bulb. Anyway, it's run fine for a year like this.
However, last night when driving home the instrument lights seemed very dim, and the battery warning light came on very briefly when the revs were low.
This morning it wouldn't start (dead battery), so I get the jump leads out and fire it up. Disconnected the jump leads and put a voltmeter on the battery and it read about 12.5V, so I assume it's not charging. So far, it looks like the alternator is dead.
However, while the engine was still running, I unplugged the signal wire (at least, i think it was the signal wire - it was the thin purple one) and suddenly the battery voltage jummps up to about 14V and the revs drop a bit suggesting there is a bit of a load on the engine.
So I assume it's now charging, and I plug the signal wire back in and go for a wee drive to charge the battery up a bit.
When I get back, I put the voltmeter back on, but now with the engine running the voltage is back to 12.5V, and unplugging the signal wire has no effect any more. But the battery has definately charged up because it starts on it's own without the jump leads.
What's going on?
Is my alternator dead?
Is there a regulator I can replace seperately?
Why does my warning light never come on?
If I ground the signal wire, should the light come on?
Cheers for any suggestions -
Leo
I'm trying to work out if my alternator is dead. I have an 1997 899 Cinquecento SX.
First of all, when I turn the key to acc. the battery warning light doesn't come on at all. It never has, and I assumed this was just the bulb. Anyway, it's run fine for a year like this.
However, last night when driving home the instrument lights seemed very dim, and the battery warning light came on very briefly when the revs were low.
This morning it wouldn't start (dead battery), so I get the jump leads out and fire it up. Disconnected the jump leads and put a voltmeter on the battery and it read about 12.5V, so I assume it's not charging. So far, it looks like the alternator is dead.
However, while the engine was still running, I unplugged the signal wire (at least, i think it was the signal wire - it was the thin purple one) and suddenly the battery voltage jummps up to about 14V and the revs drop a bit suggesting there is a bit of a load on the engine.
So I assume it's now charging, and I plug the signal wire back in and go for a wee drive to charge the battery up a bit.
When I get back, I put the voltmeter back on, but now with the engine running the voltage is back to 12.5V, and unplugging the signal wire has no effect any more. But the battery has definately charged up because it starts on it's own without the jump leads.
What's going on?
Is my alternator dead?
Is there a regulator I can replace seperately?
Why does my warning light never come on?
If I ground the signal wire, should the light come on?
Cheers for any suggestions -
Leo