This is an '81 DL Wagon with 284K. At 262K, I have records where the previous owner had new bushings installed in the alternator. The parts listing on that work order did not list new brushes. I can't believe someone would go to the trouble of replacing bushings without also replacing a $3 set of brushes, but go figure.

Symptoms started this morning. My alternator light barely came on, and the volt meter dropped to the range it has with the key-on engine-off, and it was missing a little. When I rev the engine, it starts charging again. If it quits charging at low engine speeds, it will not resume charging until I rev it up. Also, driving it home after dark, not only the alternator light is coming on, but all the lights that normally come on with the key before starting just barely glow. (Except the oil pressure light, which stays off.)

My guess is brushes. The alternator has a black rectangular box on the back of it. Does that mean it's a built-in regulator? There is a metal Bosch box on the right fender well behind the water reservoir that looks like a voltage regulator.

Can I replace the brushes without removing the alternator? All help appreciated!

I ended up replacing the entire alternator yesterday morning. $72 at Autozone, lifetime warranty. Very easy to replace. Works great.

Man, I hate spending money on parts. I've spent more on parts now than I did for the entire car in the first place. On the other hand, the money I save on labor by doing the work myself buys a lot of other fun stuff.

Good for you! Charging really is important.

Guess I got lucky with my 81 DL. Brushes did it for me; I am able to run a 4 speaker stereo and the regular safety accessories.

I've started putting any wire I have replaced into one of those flexible corrugated plastic covers, since I am too lazy to route them around the firewall. The biodegradable wiring has bitten me quite a bit, although I think I am close to ready for winter.

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__Stef -- 81 DL wagon B21A SU carb M46 314000km

"I've started putting any wire I have replaced into one of those flexible corrugated plastic covers, "
I've used teflon polytube around individual wires and bundled them with zip ties.

However the polytube is hard to find so you could use vinyl tubing which is also oil and heat resistant. Ie. the small dia. clear vinyl tubing used for water found in hardware stores.
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1980 245 Canadian B21A with SU carb and M46 trans

I was going to Dremel off the edge of the brushes that was actually contacting the commutator to allow more surface to be utilized, but I went ahead and reinstalled it the way it was, and this time the voltage slowly climbed to 13.2 while revved, where it topped off. I'm thinking that the brushes may seat into the worn commutator and start charging at the full 13.7 or 14 volts if I drive it a while. Since it's not actually discharging I should be able to drive it.

My idiot lights are glowing, but less now, and go almost completely out when I rev it off of idle. More to come later.

The brushes may eventually seat themselves. Is spring pressure sufficient?
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1980 245 Canadian B21A with SU carb and M46 trans

>>The brushes may eventually seat themselves. Is spring pressure sufficient?<<

That's what I was hoping. Yes, spring pressure seems to be adequate. But it's not charging any better and I've got over 50 miles on it.

But now I'm thinking the brushes weren't the problem. I get a stumble, like there's an intermittent short that kills the ignition just for a split-second. It never dies, and the voltmeter doesn't fluctuate when this happens though, which puzzles me.

So tomorrow I'll put it on some ramps and crawl under it to see if I can find the notorious short that is common in the biodegradable wiring of this beast.

I removed the regulator to look at how the brushes were wearing, and neither brush is flush agains the commutator. One of them is in contact barely on one edge, and the other looks like it's almost not touching anything.

There are a couple of grooves on the commutator where the previous brushes were riding, and I thought the new brushes would just fit into those grooves and work fine. Apparently not.

I may be looking at a new alternator now......

Well, I bought a new regulator (from an '84, since my alternator was upgrade to one with an internal regulator) and installed it at work today. Very easy swap. At start-up it began to charge nicely for about 5 seconds, then went back to what it was doing before.

I put a digital voltmeter on it, and while idling it's making about 12.2 volts, which was enough to drive it home without depleting the battery, but is not enough to keep the battery topped off.

What the heck is wrong with it? It has a recent battery, so those connections are clean. I used an old jumper cable to ground the alternator to the body and the engine and the battery with no change.

I guess it acts like a bad connection that ceases to connect as soon as a little current heats it up or something, but I don't know where to look.

One thing I forgot to add was that revving it off idle does cause the slightly glowing idiot lights to dim a bit. I take that to mean that it's charging slightly.

Check the tension of the Alt belts.

Good luck!
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If you listen to the radio in Portland, OR, you may know me as "Portland's Favorite Soul Brother!"

People usually have gotten the alt. replaced over the years on these; mine still has the old external regulator (which is probably fine), but the alt. has internal regulator. I'm not saying this as an endorsement of the idea, just that it has usually been done.

I just dealt with this on the weekend. Please don't replace your alternator. You probably only need brushes. A reputable starter/alternator shop can do the job and confirm correct operation on their bench. You just need to bring them the device. This was the route I went and it was inexpensive albeit gruntish.

I could have just ordered a new VR/brush set; this is a trivially easy job.

You don't GET a new alternator when you replace. You get one that is functionally exactly the same as your old one, used, with its problem repaired, (which you should have done anyway) with a shiny appearance. Dirt does not affect alternators, which is an external device.

Some business. They get your perfectly fine old one for peanuts, fix it for next to nothing to sell to the next guy, gouge you on a used replacement that cost them nothing to "rebuild", and you are okay with this because they have the "expertise".

The "alternator" is a simple, robust device, _somewhat_ like your "car". If "car" has trouble, you think long and hard about replacing the whole thing, and you do your homework. Too many people turn off their brain and open their wallet when it comes to automotive electrical systems.

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__Stef -- 81 DL wagon B21A SU carb M46 314000km

Respectfully, I have to disagree with Mike and agree with Bob. Buying a new alternator because of bad brushes is wasteful in the extreme. The symptoms you describe are typical of bad brushes. I had to change out a pair one month ago. There is no real problem getting to the bolts holding the internal regulator to the alternator (unless alternators on 1981 240s are a lot different than those on a 1988), and there is plenty of space in the engine bay of a 240 with a four cylinder motor. I changed a set last month without removing the alternator. The job took about one hour.

Take part of the money you'll save on the unneeded alternator and invest it into a VDO voltage gauge. This is a great way to keep track of the health of your electrical system. You can tell when the brushes first begin to fail.
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'88 244GL, '89 244GL, '90 244DL, '91 244, '92 244

>>Take part of the money you'll save on the unneeded alternator and invest it into a VDO voltage gauge.<<

It already has a factory volt meter in the dash. In my original post I referred to it going down to where it is with the key-on engine-off (not charging.) Then it would go back up to normal, well into the green (no numbers on this gauge) after revving it up.

Thanks! I'll be picking up some brushes today!

Ken

Do a simple diagnostic test before you start changing the alternator brushes. Fully charge your battery to 12.6 Volts. Measure the voltage with the engine off. Turn on the engine. Your voltage should be 13.8-14.8 Volts. Less than 13.8 Volts means you need to check the fan belt tension and replace the entire alternator and/or the alternator wires. More than 14.8 Volts means your voltage regulator is faulty. The purpose of the voltage regulator is to prevent high voltage charging of the battery, and thus explosions.

I personally would replace the entire alternator. The two flat-head screws that hold the voltage regulator to the alternator are difficult at best to remove even when the alternator is outside the car. Imagine how difficult they are to remove in the narrow engine bay! Next, do you think that you want to risk the alternator going out on you after your replace the voltage regulator? You can get a replacement alternator with a lifetime warranty for less than $160 at Kragen or Pep Boys.

Finally, I would clean the contacts on the dash/idiot battery light and change the bulb. On my 1989, the battery idiot light is connected in series between the alternator and battery. If that light burns out, the alternator won't charge the battery. What a shitty design!

Please e-mail me the results of your work

Mike
menaster@yahoo.com

>>You can get a replacement alternator with a lifetime warranty for less than $160 at Kragen or Pep Boys.<<

I can get a replacement alternator with a lifetime warranty for $71 at Autozone.

Problem is, I only spent $200 on this car. And it's got relatively new alternator bushings. If I can fix it for 3 or 4 bucks, that's what I'm going to do. And it looks like I can get to the back of the alternator fairly easily while it's in the car.

Thanks for your input!

Ken

Your brick may or may not have the external regulator system. When I converted one of mine to internal I just left the old external unit on the fender and discarded the connecting wiring harness.

You have about nailed the problem. I would go for new brushes, and quickly. They can be installed without pulling the alternator.

The black box on the back of the alternator is indeed the brush set and the internal regulator, you get both new with a new set.

BE SURE to disconnect the ground connection at the battery before beginning the job. The big red wire connected at the back of the alternator is always hot. It is an easy job. Allow a half day for your first time.

With the brush set out, use a mirror and flashlight to look inside the alternator to see the slip ring condition and to see how to maneuver the new brushes back in. They must ride properly on the slip rings.

When the brushes get worn way down, below 3 mm long, the connection with the slip rings gets weak, and there can be arcing that can pit and damage the slip rings. That's why to fix it quick.

Good Luck,

Bob

:>)

before i give him some wrong info, is the '81 alternator the same as the later ones i.e. 1989??
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'75 Jeep CJ5 345Hp ChevyPwrd, two motorcycles, '85 Pickup: The '89 Volvo is the newest vehicle I own. it wasn't Volvos safety , it was Longevity that sold me

my 81 has the 55 amp; it has no high draw accessories beyond the safety stuff (lights, rear window grid, wipers, heater fan).

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__Stef; 81 DL wagon B21A SU carb M46 __313k

I have some Pics of the alternator and pulling the Brush/regulator off of it. Is that part of the alternator the same?
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'75 Jeep CJ5 345Hp ChevyPwrd, two motorcycles, '85 Pickup: The '89 Volvo is the newest vehicle I own. it wasn't Volvos safety , it was Longevity that sold me