Hey guys, my wife drives an 02 Outback. We have only had it for about 3 months. Something weird has started happening with it. This only happens when it is cold outside. When she starts it in the morning, the battery light and the brake light stay on. The idle is fine on the car, but the dash lights are only about half as bright as normal and the fan for the heater is only running at about half speed. The car will stay this way until you tach it up to about 3 grand, then both lights will go out, the lights go full brightness, and the fan goes full speed. Does anyone know what could cause this?

 

> Does anyone know what could cause this?

Since you own a Ford, I will answer this because it is a general statement, though "real" tech questions should go to a Subaru board, if one even exists.

Unlike domestic, most overseas cars have an alternator that will not charge once voltage drops to a certain level, around 8-10 volts depending on alternator OEM, to save the alternator and built in regulator. Most Haynes manuals (got one for your Outback?) even state this.

You can still start a small engine in warm weather with 9.6 volts. I have found when replacing an alternator in a VW, etc. once you install the alternator, the only way to get it to start charging is by reving the engine to 3k or more. Then it will start charging and go happily along its way. If battery voltage drops again (lamps on - batt. dead) the only way to trick the alt into charging even after the battery has been charged, is by bringing the engine to 3k+.

Before starting the car, check your battery voltage. Then check it once it is running. Then check it once you rev it and it starts to run. Most likely you have a weak battery if it is the stock unit.

If you charge the battery with the cables attached you will most likely blow the reg. (or diode) inside the alt., so do not do it. I would not recommend jump starting someone either since the Bosch and Jap. alternators pretty much hate it when people do not follow correct hookup procedure (not direct battery to battery for ground).

 

Thanks for the reply rebocardo. I did try to find a Subaru board, but found none that where very populated. I figured I would get more of a response on here. I will do what you suggested. Thanks again!!!

 

You might try this site if you haven't found it (and assuming it's still up):

http://www.nasioc.com

That's the North American Subaru Impreza Owner's Club. However, I was not impressed when trying to get some information on a problem on the wife's Forester.

You won't find anything like FTE, it's in a class of its own....kudos Ken.

 

You are welcome. I thought I would mention that there might be an unused (+) terminal on the back of your alternator, do not use a test light on it (basically bringing it to ground) or you might blow the reg., it is for turning the alt. on in some vehicles from an ign. based switch on some cars (VWs).