Batt Light(and several others) ON, 11.7v DC, no AC voltage. Alternator???

CDG · #1 07-04-2006, 08:12 PM

I have what appears to be a simple Alternator failure. This occured not 40 minutes ago when I backed into my garage on this very hot sunny 4th of July Tuesday.
With the accompanying cluster of several other lights on: Steering(never knew I had a light for that), Stop Lamp, Brake and ABS lights also on.

However, before I replace an alternator I wanted to check a few things:
1)Removed the Battery Wire Upgrade(bypasses the Fusable Link) and
2)checked the fusable link, its OK.
3)Check for AC current, and none would register, not surprising if the alternator is indeed toast.
4) Checked the battery voltage at the alternator and the battery, both are 11.70 and slowly falling.
5)Obviously checked the belt, and its attached and turning the alternator.

Q: are there any other tests I can run before coughing up $250 for an alternator?
Or is a new alternator my next test?

btw, searched and read too many electrical issue threads and I'm getting scared that its not an alternator at all, but something more scary, light the Gremlin infesting my garage

Earthworm · #2 07-04-2006, 08:14 PM

Make sure the plug on the alternator is not loose. That's about all I can think of. Better look up the $55 alternator fix posted by Beav.

CDG · #3 07-04-2006, 10:02 PM

Quote:

Originally Posted by Earthworm

Make sure the plug on the alternator is not loose. That's about all I can think of. Better look up the $55 alternator fix posted by Beav.

OK, Found Beav's Alt fix. Looks good.
http://www.subaru-svx.net/forum/showthread.php?t=21852

I found the rectifier(IMR10068) here: http://195.125.241.148/cgi-win/product.exe?IMR10068
And the Regulator(IM277) here: http://195.125.241.148/cgi-win/product.exe?IM277

I want to make sure that I need an alternator(or Regulator/rectifier) before I start the process.

Does anybody know what voltages I should see on the 2 wires going into the alternator to start the Magnetic field?
I'd like to check those to make sure I'm getting a trigger voltage for the field. Is it just 12v?

Manarius · #4 07-04-2006, 10:34 PM

I'd go have the alt's voltage tested before you just go and cough up for parts money. Head over to autozone or something and have it load-tested. But, all those lights come on usually when there's an issue with the charging system...

CDG · #5 07-04-2006, 11:44 PM

Quote:

Originally Posted by Manarius

I'd go have the alt's voltage tested before you just go and cough up for parts money. Head over to autozone or something and have it load-tested. But, all those lights come on usually when there's an issue with the charging system...

Thx Jason, I think there is definately a charging issue, but I just want to test the Field and make sure its getting something, maybe there's a fuse?

Beav · #6 07-05-2006, 04:25 PM

It's definitely the rectifier and I wouldn't replace it without the regulator also.

It's a typical scenario in the summer: hotter than heck, a/c on/ blower on max, engine hot and idling in traffic and the rad fans blowing hot air into the alternator. It doesn't stand a chance. Shoot, I've even seen alternators quit charging because the solder joints have been weakened by heat build-up. GM even has a water cooled alternator for some of its big cars that have high electrical loads - Caddy, etc. The whole idea is to get the rectifier cooled down before it melts. It's also another reason why we'll be going to 48 volt systems soon.

Suby Fan · #7 07-05-2006, 04:34 PM

ok the simple way to test if your alternator is bad is to start the car and take the negitive battery post off the battery if the car stalls its bad

Beav · #8 07-05-2006, 04:56 PM

And so is the numb nut that does that. The voltage can shoot up over 16 volts in a heartbeat and blow every light bulb (that's turned on) and electronic device in the car!

CDG · #9 07-05-2006, 05:50 PM

I'm relatively confident that the Alts gone the way of the DoDo bird.
Called around and a place near my house is going to rebuild it for $75-120. Can't complain, will check in tomorrow or the next day with results. Taking it to them right now.

CDG · #10 07-05-2006, 06:27 PM

Well, I dropped it off and he bumped up the price to $140. but it will be done tomorrow, so It better be nice enough to eat off for that price.
I think I just got hosed, sweat talking techy

Beav · #11 07-05-2006, 06:57 PM

Depends on the warranty...

CDG · #12 07-05-2006, 07:03 PM

1 year, best around..apparently

CDG · #13 07-06-2006, 06:49 PM

Well, picked up the rebuilt alternator, and yes, it was clean enough to eat off of.

I looked and he didn't replace the Rectifier, cause I etched before I droped it off, and I saw the same one in the alternator.
Anyways, still comes with a 1 year warrantee and its working fine.
so far.

Sounds like a routine alternator replacement. Thank God.