Faded

If anyone could help me I would appreciate it.

The charging system in my '90 4-R is all jacked up. I believe it began a while ago at the car wash. I was planning on doing some engine work so I was going to clean the engine compartment. I misted the motor with Castrol Super Clean and used the pressure washer to hose everything down. I was carefull not to direct the high pressure spray directly at the distributor and the alternator, but maybe I wasn't careful enough?

Anyway, a day or so after the car wash I get the flickering brake and battery lights, but everything seems to be normal. I went ahead and ordered new brushes anyway knowing that they're probably due for replacement. While waiting for the brushes the battery went completely dead overnight. Nothing was left on so I really can't explain this one. Luckily the battery was still under warranty so I went it and had it replaced after it tested bad. With the new battery the charging system went crazy. The volt meter in the dash was dang near pegged at 18v and the battery and brake lights in the dash were constantly on. I turned on both front and rear heaters, the radio and the headlights in order to get a voltage drop to try and keep from damaging the system. This brought the voltage down and would keep the battery and brake lights off most of the time. It seems during this time that the system was overcharging? This went on for about 3 days. After this the alternator wouldn't do crap, the voltage dropped near the bottom of the 'normal' level and it was obvious that the 4-R was running strictly on batter juice.

I finally pulled the alternator to replace the brushes and the old ones looked house, about 85-90% the size of the new ones. I went ahead and replaced them anyway and cleaned up all the contact areas. This didn't do anything for me and the system still isn't charging.

Anyone have any ideas on what could be going on?

tc

Battery terminals nice and tight? If there is slop, the alternator will read funny and sometimes do what you're talking about.

Faded

Yes, everything is nice and tight and corrosion free.

DudeBud

if you havent already take the alt to get tested, could be a bad regulator or diode

snap-on

I thought toyota used externally regulated alternators? (i can never remember)

DudeBud

they do pre 85 years but that dosent mean they cant go bad.

Faded

Called my buddy at the salvage yard and he hooked me up with a used one - $35. Went home and slapped it in and it works fine. As far as I can tell it looks as if both are internally regulated. Still don't know what's wrong with the old one. Thank you for the replys, didn't want a new alternator for $150+ that the parts stores were asking, but for $35 I couldn't go wrong.