internal or external regulator, 50 amp or 60 amp alternator

[ulan]

long story long my 87 dies when i push my brakes or turn on the headlights, brake light on charge light on brake rez full ect. found out i need a new alternator, im pretty sure i have an internal volt regulator so the next question is there any way to find out what alternator i need? i pulled the old one off but cant find anything on the tag indicating how many amps. its an 87 4wd wagon.

thanks for reading

[Petros]

Welcome to the list!

I have only seen the external regulator type the '83-84 model year (and those seem random, no way to tell which get them and which do not). I think '85 and later all have internal regulator, which is what you should have. No external way to tell AFAIK, they look the same, but connector is different.

The regulator is a little black box connected to the wire bundle on the left (driver's) side fender (in USA), behind the battery. If you just see wire bundle and no electrical device on the side of the inside fender well behind the battery, you have the internal regulator. Also, the connector in the alternator is different, so if it plugs into your wire harness, you have the correct alternator.

Where are you located?

[ARCHINSTL]

Look at this page on Advance's site http://shop.advanceautoparts.com/webapp ... meClicked= ; the IC alternators are at the top of the page and the non-IC is at the bottom. Also look in the FSM on pages CH-7 and CH-22 for diagrams.
Tom M.

[ulan]

thanks guys this all helps out alot. love how the forum people always pull through. located in seattle and duvall lol...
one more question they guys at nix99 said the wagons can run either 50 or 60 amp alternators...besides cost any perks to running the bigger vs smaller and vise-versa?

[Highlander]

The 55 amp external regulator is factory for '85 and on. It's actually smaller than the 50 amp internally reg. As long as it fits and the plug is right, no downside to more output in my mind.

[Petros]

I suppose the smaller one weighs less, can not imagine why you would need the larger one.

However I did have an Interesting experience with my daughter's Suzuki; she ran the battery dead and it stopped running, even though the alternator was putting out power fine. The stupid thing has the head lights on all the time when in drive, not even a way to override the head lights to "off" without unplugging them. Her battery was getting old, but still started the car fine, she was driving to class and it just died, would not restart. Of course when there is car trouble all my women call me first, no matter where they are. She walked the last few blocks to class while I drove over to her car with an extra battery (actually a Tercel battery, much larger than the one for the Suzuki). I checked the voltage on her battery and it was about 9 volts, not enough to start. I put in the larger TErcel battery (got it to fit by removing the plastic tray). It started up just fine, checked the voltage 13.9-14.2 volts, so alternator was putting out. I thought I would test how much excess capacity it had, so I turned on the headlights (when the car is in park the headlights are off unless you manually turn them on), and the voltage dropped to 11.4. I looked around and the electric rear window defroster was on (radio was off). I turned off the defroster and the voltage came back up to just over 13 volts. So it appears if the defroster and head lights were on it would draw down the battery, and in her case she drove also with the radio blaring, so it will run until the battery is completely out. This would kill the car since you have to have a battery in it to run all of the modern electronics. There was once a time after the car was started you can take out the battery and it would run without it, not any more.

I drove it home with the head lights unplugged to charge up the battery (defroster off). We replaced the battery with a new one but I told her not to run the rear window defroster any longer than she needs to get the frost/fog off of it. She was not even aware that she was driving with it on (despite the fact that a little orange LED was glowing right in the middle of the switch!). Appearantly she would always leave it on, drive with the headlights on, and the radio blasting, with the heater on full. That would be hard on any battery, but that electric defrosters draws a lot of power, more than the alternator can put out.

So if you are putting high powered head lights, extra fog lights, more speakers, etc. it is possible you will need the extra large alternator. Or you can get stuck when you do not expect it.

[ARCHINSTL]

The 55 amp external regulator is factory for '85 and on. It's actually smaller than the 50 amp internally reg. As long as it fits and the plug is right, no downside to more output in my mind.

My '86, with what appears to be the OE alt, is internal. I thought all of the later cars were.
Tom M.

[Petros]

I have owned two '85s, one 86 and an 87, all had the internal voltage regulator. I have owned four '83 or '84, only one had the external regulator alternator.

[Highlander]

I've had 3 '83s, all without internal regulator (the larger, physically, alternator) and 3 '85s all with the internal regulator (smaller alternator). I just ran outside to the '83 SR5 and checked that against the FSM, and Tom is right, the internally regulated is the later, smaller alternator. According to the FSM, the non-regulated one has both connections on the rear of the alternator, while the internally regulated has one connection on the top.