My issues started 2 weeks ago when I noticed the battery/abs/handbrake lights all flash up whilst I was driving. They went away a few seconds later and I thought nothing of it. A few days later this happened again, they stayed up for around 30 seconds in which time I gave the brakes a good test to make sure ABS was working, which it was; they then went away again.

Now a couple of days ago they came up around 2 minutes from my house, pulling into my driveway the handbrake/abs lights went out but the battery one was still illuminated. At this point I was tired so I turned the car off and thought I would check things over in the morning. The next morning my car wouldn't start due to a flat battery. Testing the battery with my multimeter revealed it had dropped to 1.8v.... not good at all.

I got a new battery and put it in this morning, car started fine but battery light was still up. I noticed a whining noise from the engine coming from around the alternator area that I don't remember hearing before. It was a high pitched sound and varied in pitch with the revs. I measured the battery terminals with my multimeter again whilst the car was running and it showed 18v. I turned the car off immediately and measured again, 12.9v.... I then started the car and removed the negative battery lead, measuring again with the battery disconnected showed 25v on the leads! I tested a quick rev to see if the volts would increase with revs and the car immediately stalled and the windscreen wipers moved a bit by themselves :shock:

Now when I connect the battery and turn the ignition on, the windscreen wipers turn on and will not stop. I tried moving the wiper control arm down/up but it just makes them go faster/slower. I would imagine that the relay has been damaged by the excess voltage output from the alternator but that problem I will tackle later. For now I want to know what everyone's thoughts are as to why the alternator is outputting way too many volts. I'm not sure if they have some sort of regulator that can be checked/replaced? I am also unsure as to how the original battery was drained overnight, perhaps it was damaged due to overcharging but I'm not sure. I have checked various things to make sure nothing was on and draining the battery but couldn't find anything.

If anyone else has experienced similar issues and can shed some light on this it would be much appreciated.

similar problems occuring on my old boys patrol but at 15.5volts, should charge at 14.4 average, seems like u need a re-con alternator/new one. not sure how hard it is to change the regulator on these...

Probably the voltage regulator. Should be approx $80 to replace but might be a good idea to get the whole alternator checked out / reconditioned in the process.

I'd say you cooked the battery by overcharging due to the faulty regulater in the alternator which probably caused all the warning lights to come on the first time....then taking the neg lead off when the engine was running was not the best idea as the alternator voltage just keeps climbing. The wiper on all the time would make me think the ECU is fried as well. I've seen similar on a Commodore (similar alt) where the battery lead came off and every component that was in circuit was cactus - ECU, BCM, allbulbs as it was nighttime and the alternator itself. Starter and battery were OK.
So I think you may discover the problem is a bit bigger than first thought. Hopefully I'm totally wrong.

So I think you may discover the problem is a bit bigger than first thought. Hopefully I'm totally wrong.
I ran the car with the alternator disconnected quickly to test and all seems fine except the damn wipers won't switch off. I have pulled the regulator off and will be chasing a new one on Monday.

Are the wipers controlled by the ecu? I had a quick look and couldn't find a relay for them, I found the fuse under the drivers side dash but as I said no relay that I could see.

I ran the car with the alternator disconnected quickly to test and all seems fine except the damn wipers won't switch off. I have pulled the regulator off and will be chasing a new one on Monday.

Are the wipers controlled by the ecu? I had a quick look and couldn't find a relay for them, I found the fuse under the drivers side dash but as I said no relay that I could see.

the problem could also be a symptom of a blown diode in the rectifier (basically the reg senses low output and switches the rotor on hard but then cant recover fast enough when the next working field barks out up to 36 volts)
another thing to consider is the condition of the stator.... if it has been overcharging then the insulators (plastic) may have melted and or the windings may have started to burn.

try disconnecting the wiper switch as all the electronics for the intermittent position are inside (including a small relay that may have fused contacts). if that doesnt stop the wipers then the problem may be in the motor itself (fused timing contacts).

Picked up a new regulator today for $40, put it in and started fine. Measured a healthy 13.5-14v at the bat but I noticed a burning smell coming from the alternator. Seems the windings are damaged from earlier so chasing up a whole new alt now.

As for damage to the electrical system it looks like it was limited to the wiper issue and interior light which blew so I'm lucky in that regards. So glad my ECU wasn't fried :)

What are some normal prices for a new alternator? I'll ring around tomorrow.

Last time I looked:

Wreckers = $50
Recon job with warranty = $150
New = $350

Rough idea anyway.
It's normal for a stressed alternator to be a bit on the nose - overheated insulation smells! Nothing to worry about, provided the output is stable.

It's normal for a stressed alternator to be a bit on the nose - overheated insulation smells! Nothing to worry about, provided the output is stable.

Not when they start smoking :P

Thanks for the pricing, it's in line with what I had in mind.

Got a new alternator today for $210, came home from work and swapped it over. All seems good now, the battery is being charged at the correct voltage and taking it for a spin around the block reveals no more electrical components were damaged. You just can't kill 'em :P