1986 Turbo Xt With Digital Dash. The Battery Is Good And I Took The Alternator To 3 Different Parts Stores And It Tested Good. One Person Said It Might Be A Fuse Or Wire From The Alternator. Another Sais It Could Be A Passive Ground. Anyone Have Any Suggestions As To What To Look At?

Thanks!!!!

How do you know the battery is good? Did you have them charge test it? Swap it with the battery from another car if you are able to.

 

What is the voltage reading across the battery terminals while the car is running? It should read near 14v.

 

Is the alternator grounded properly? I've had the ground wire melt off an alternator because corrosion built up resistance, and eventually created enough heat to slag the fitting. Try tying a thick gauge wire between the case ground and the negative battery terminal. Check and clean all of the body grounds you can find in your engine bay.

 

Are the battery terminals clean?

 

On Subarus I believe the regulator is either in the alternator, or mounted on the fender. Which is yours? If it's fender-mounted, it's possible it's malfunctioning.

 

Hope some of that helps.

Have you checked the tension on the fan belt that runs the alternator?

I would take the car to the auto parts store. They can check the charging system on the car, which might help you out. I always look at battery terminals first when there's a starting or charging problem.

http://www.ultimatesubaru.org/forum/showthread.php?t=46624

 

I would peruse this thread, especially when it gets into electrical testing procedures a little later on.

 

Good luck!

How do you know the battery is good? Did you have them charge test it? Swap it with the battery from another car if you are able to.

 

What is the voltage reading across the battery terminals while the car is running? It should read near 14v.

 

Is the alternator grounded properly? I've had the ground wire melt off an alternator because corrosion built up resistance, and eventually created enough heat to slag the fitting. Try tying a thick gauge wire between the case ground and the negative battery terminal. Check and clean all of the body grounds you can find in your engine bay.

 

Are the battery terminals clean?

 

On Subarus I believe the regulator is either in the alternator, or mounted on the fender. Which is yours? If it's fender-mounted, it's possible it's malfunctioning.

 

Hope some of that helps.

 

THANKS FOR THE REPLY. I DROVE THE CAR TO A PARTS STORE AND THEY TESTED THE CHARGING SYSTEM. THEY SAID BATTERY WAS OKAY BUT NO READING FOR ALTERNATOR EXCEPT "CHECK WIRE". ALTERNATOR CHECKED OKAY WHEN TESTED OUT OF CAR. NEW GROUND WIRE WAS PUT IN BY SUBARU MECHANIC 4 WEEKS AGO. BATTERY TERMINALS ARE VERY CLEAN. BELT IS TIGHT. HAVE USED DIFFERENT BATTERY WITH SAME RESULT. I BELIEVE THE REGULATOR IS ON THE ALTERNATOR. I PUT A CHARGER ON THE BATTERY AND FULLY CHARGED IT. WHEN I PUT IT BACK IN THE CAR IT READ 12.8 VOLTS WITH THE ENGINE OFF. IT READS 12.3 VOLTS WITH THE ENGINE RUNNING. FUNNY THING ABOUT IT IS THAT WHEN I FIRST PUT THE ALTERNATOR BACK IN THE CAR THE VOLTAGE AT THE BATTERY READ 14.4 VOLTS WITH THE ENGINE RUNNING.ABOUT TWO DAYS LATER IT STOPPED READING THAT HIGH AND NOW READS 12.3 AND LOWER AS THE BATTERY DRAINS. ACCORDING TO 3 AUTOPARTS STORES, THE ALTERNATOR IS OKAY BUT IT DOESN'T APPEAR TO BE SENDING THE CHARGE TO THE BATTERY.

Check the voltage as it comes out of the alternator; if it's above 14VDC there and only 12V at the battery you likely have a bad battery cable. My suspicion is the alternator is bad even though it tested good outside of the car.

I agree, it's possible the alternator has an intermittant problem. Loose connection, bad solder joint... something like that.

Check the fusible links for a problem there. Make sure they are all good. If they are ok then measure the voltage of all the connections to the alternator with the engine running. They all should read close to the battery voltage if things are ok. Also make sure that the warning lights turn on when you turn the ignition to RUN and don't start the engine. You are most likely going to find the problem in one of these areas.

http://www.ultimatesubaru.org/forum/showthread.php?t=46624

 

I would peruse this thread, especially when it gets into electrical testing procedures a little later on.

 

Good luck!

 

THANK YOU! THAT WAS A GOOD THREAD TO PERUSE. THIS WEEKEND I WILL DO SOME VOLTAGE DROP TESTING AND SOME SERIOUS GROUND TESTING. ALSO WILL HAVE BATTERY AND ALTERNATOR CHECKED AGAIN.

Check the fusible links for a problem there. Make sure they are all good. If they are ok then measure the voltage of all the connections to the alternator with the engine running. They all should read close to the battery voltage if things are ok. Also make sure that the warning lights turn on when you turn the ignition to RUN and don't start the engine. You are most likely going to find the problem in one of these areas.

 

TWO WARNING LIGHTS ON WHEN IGNITION IS ON RUN (WITHOUT STARTING ENGINE) "EGR" AND "BATTERY". I WILL CHECK VOLTAGES AND LINKS THIS WEEKEND. ONE THING I FORGOT TO MENTI0N THOUGH, IF IT MEANS ANYTHING, THE RPM DISPLAY ON THE DIGITAL DASH DOES NOT FULLY LIGHT UP SOMETIMES. PARTS OF THE NUMBERS WILL NOT SHOW AND THAN AFTER DRIVING SEVERAL MILES THEY WILL START TO FULLY SHOW. THANKS FOR YOUR INPUT:)

Check the voltage as it comes out of the alternator; if it's above 14VDC there and only 12V at the battery you likely have a bad battery cable. My suspicion is the alternator is bad even though it tested good outside of the car.

THANKS! WHEN YOU SAY CHECK VOLTAGE AT ALTERNATOR, DO YOU MEAN AT THE SINGLE THREADED CONNECTION THAT THE HEAVY GUAGE WIRE IS CONNECTED TO,... OR THE PLASTIC CONNECTOR?

The heavy wire connector is the one which should output the voltage to the battery.

THANKS! WHEN YOU SAY CHECK VOLTAGE AT ALTERNATOR, DO YOU MEAN AT THE SINGLE THREADED CONNECTION THAT THE HEAVY GUAGE WIRE IS CONNECTED TO,... OR THE PLASTIC CONNECTOR?