Battery light comes on

[arbik]

Hello all,

So the battery light in the D90 comes on, randomly at times. And then goes out...randomly.
this had been happening a few months ago, so I hooked up a multi-meter to the cigarette lighter port inside, and when it came on, I would monitor the voltage...
no change in voltage.
Then it went away...for a few months...
now its back again (could it be the cooler weather?)
Randomly, it'll turn on, no matter where I am, and how fast I'm going..
sometimes, it'll stay on for a while..then go away, other times, it'll come on..and go out in a few seconds.

Its driving me nutz.

any ideas?

thanks,

-arbi

[Red90]

Most likely your rectifier is going bad. Find a place that test alternators (most mechanics, but best to see an auto electrical shop) and get it tested ASAP. If it is the rectifier, you are getting AC voltage out into the electrics. This starts to fry everything.

When this happened to me I lost an ignition module, a coil and a batery before I realised that it was the rectifier causing it all.

[arbik]

but if its putting out AC voltage, then wouldnt my multimeter not show the DC voltage?
I have a FLUKE and it identifies the type of voltage.
Non the less, I'll take it in, and have it checked out...
might just be a good idea, to change the alternator, belts and the waterpump all in one sitting.
they're probably overdue to go back anyway.


thanks,

-arbi

[Red90]

No, you are still getting the DC but with AC fluctuations. An alternator produces an AC current. The rectifier is a group of diodes that cuts off the bottom of the AC signal to give an approximation of a proper DC signal. If you lose one of the diodes, you will get peaks from one of the phases at a higher voltage. The multimeter shows an RMS (root mean squared) DC voltage, sort of an averaging. Anyway, these peaks are like having voltage spikes. The spikes are hard on many electrical items. Any Auto electrical can test it in 5 minutes and it is usually free.

Here is a good link (http://members.1stconnect.com/anozira/SiteTops/energy/Alternator/alternator.htm)

[arbik]

Hi John,

Thanks for the info. I'll have it tested.

-arbi

[DJ Menasco]

Arbi

Did you figure out what the problem was?

DJ