87 RX eratic amp gauge

[87 TurboReX]

Hi folks,

 

I recently purchased a 1987 Subaru RX turbo AWD. (Pictures (if anyones interested) and possible other info later)

 

It's the 3 door coupe, it's the familiar white and yes it came with the white plastic wheel covers. It runs pretty well, the interior is in really good shape with no dash cracks or rips other than in the drivers seat which is slated for repair.

 

It had a little rust around the fenders which I removed with naval jelly and sealed it and spray painted it white for now till I can do a real repair. It's my daily driver and a fun way to get to work (especially through a Missouri snowstorm) but there are a few mechanical repairs I need to make.

 

At the top of the list is an apparent electric problem that is as follows and perhaps others with this car (or similar) have encounted this also. I would appreciate any insight others have had along these lines:

 

First the amp meter in the car runs often on about 18 volts and seems almost "pegged out" especially for about 15 minutes or so after starting the car. While this might not be unusual (for this car?) the lights often 'pulse' and the amp meter guage needle swings back and forth in the 12 to 18 volt range as the lights are pulsing dim and bright.

 

My first thought was that it was the voltage regulator or such so I went to O'Reilly Automotive and a guy came out and tested my alternator with a meter and said it had a diode that was bad. He checked the battery and said "wow!" you have a heck of a battery it is reading 100%. I was also told by someone else that bad brushes inside the alternator could cause this light pulsing effect. (It also makes the red lights inside the car glow faintly sometimes at certain idle).

 

So what does anyone think is the culprit here? A regulator? A diode? Bad brushes? A bad connection? A belt perhaps? I'm wondering if something is not shutting offf and may damage my battery by overcharging. My car stereo went out but yet the internal fuse was still OK inside the unit. (I wondered if high voltage might have burned it out). The clock acts strange too dimming and getting bright.) I purchased a remanufactured alternator today from O'Reilly's but haven't put it on yet. The guy that sold it wasn't sure if it had an internal regulator or not but it had several plugs into it so we assumed it had the internal one. Anyone know. Does the typical EA82T engine from 87 use an alternator with an internal regulator especially on the RX AWD.(I think the replacement I bought is supposed to put out 60Amps. Is this right for this car?

 

Thoughts anyone? Thanks.

[subynut]

18 volts?? YIKES! It does sound like the regulator is shot in the alternator. I would say you are on the right track. Swap out the alternator, that sould fixy it.