If you have a early model Toyota 4Runner or pickup truck, and the charge and brake lights on the dash light up at the same time, chances are your alternator is on the verge of taking a dump, even if it shows no problems. This is exactly what happened to me. The brake light first came on for a day or 2. I checked everything related to the brakes, and all was good. Then all of the sudden the charge light and brake light lit up at the same time. But still, all was good. Battery read 13 volts while running. After a few days I had a major problem. On my way home from work, all of the sudden the CD player quit working, and my dash lights got dim. I looked at the volt meter in the dash, and it read about half charged. I began to put the turn signal on to get into the other lane, and the voltage dropped below half way. I gassed it, but the motor cut out, and the headlights went dim. Great, my alternator took a dump on me. But I made it home on my own!
Not to worry though, a cheap fix is out there. Most uninformed people would look to replace the whole alternator for anywhere from $200 to $400. But all that is needed is a new set of brushes for $10-$20! You can find these brushes at any Parts America chain, or directly from the dealer using part number 27370-35060. Go with the dealer part, I will explain to you why a little bit later.
Tools for the job are as follows.
* Metric sockets consisting of 8mm, 10mm, 12mm, and 14mm.
* Medium sized screwdriver
* crow bar or long thick screwdriver to put tension on the belt
* soldering iron and solder if you are in a bind and can't get the Toyota part
* Wire cutters for the above situation to cut the excess wire off of the brushes
* Wide jaw pliers to compress the clamps on the hoses on the air box
* pen and paper, or masking tape to mark the spark plugs and distributor for easy re-assembly
First thing to do is disconnect the negative battery terminal. Now find the alternator, and get friendly with all the surrounding parts.
To make things easier, you will need to get a few things out of the way. First start by removing the spark plug wires, the distributor cap, and the rotor. Mark your spark plug wires and the distributor cap so you remember where they go back. Grab a 8mm socket to take off the distributor cap bolts, it's a really tight fit with a screwdriver. Next, remove the 2 small hoses that connect to your air box, to the right of the radiator. It should look something like this, but with the alternator still in there! (minus all the dirt and crud you see on my poor engine)
There are a few wires that need to be removed from the alternator. There's one with a boot over it, to the side. Grab your 10mm socket and remove the nut that holds the cable on. Remove the cable. Right behind this wire is a larger wire harness that is plugged into the back of the alternator. Remove it by squeezing it and pulling away. Small hands come in handy here. Now you will have another one wire harness and a plastic clip that is clipped to the alternator body on the underside of the alternator. Unplug the wire, and use a screwdriver or something to pry off the plastic clip holding the wire onto the alternator.
Now you will remove the lower adjusting bolt. Grab your 12mm socket for this. Once it's loosened, it should relieve tension on the belt. Push on the belt to see how tight it is, and remember to tighten it like it was when you reinstall it. Go ahead and remove the belt from the pulley. Next, remove the upper pivot bolt. Grab your 14mm socket for this one. The alternator should now be free from the brackets. Grab it and pull it out of the engine bay. You will now see why you removed the 2 hoses from the air box.
Grab a 10mm socket, and remove the nut that holds the positive battery connection to the alternator, and pull the plastic boot off. It should look like this.
Grab a 8mm socket, and remove the 3 recessed nuts that hold the cover on. This will expose the brush holder and the rubber boot. It will look like this.
Grab your phillips head screwdriver and remove the 2 screws that hold the brush holder in place. Be careful to use the right sized screwdriver, as the screws are in there pretty good, and strip easily. Pull the rubber boot off and inspect the brushes. They should stick out pretty far and have a spring effect to them. Mine were short and stubby, and uneven. Here's how they looked.
Now comes the fun part, which turned out to be the hardest part of this repair. I called around a few dealers in my area, and nobody had the part 27370-35060 in stock. They said it would take at least a day to get the part in, and I needed the truck to be running the same day. So I had to go to a local parts place, Advance Auto Parts, which is a Parts America chain, to find the part. This is where I went wrong. The part from Toyota is a complete brush set, including the holder you see pictured above. The parts store part was the 2 little metal brushes, with a long wire attached to each. The brushes have copper leads attached to them that runs though the middle of a spring, and then goes out the back of the brush holder, and is soldered in place. The Toyota part requires no soldering, just replace the whole thing and be on your way. But the parts store part requires de-soldering the old brushes, routing the copper wire though the spring and out the back of the holder, and soldering it back into place. The was a major PITA. Save yourself the trouble and order the Toyota part as soon as your charge light comes on. The Toyota part retails for $17 and the parts store part was $9.
Once you get the new brushes in, compress the brushes and stick it on the shaft of the alternator, and put the screws back into place. Go ahead and bolt the cover back on, and the boot for the positive terminal. Your ready to put the alternator back in. It's that easy!
Put the alternator back in place, and loosely tighten the upper and lower mounting bolts. Slip the belt back on the pulley. Now, grab a crow bar or a long thick screwdriver. Use this to put tension on the belt. Stick it in between the motor and the alternator, and pull on it. Now tighten the lower bolt while keeping pressure on the crowbar. Here's how it looks.
When you have sufficient tension on the belt, go ahead and tighten up the upper bolt. Put back the 3 wires you removed from the alternator. Install your rotor followed by the distributor cap. Re-install the spark plugs wires on the distributor in the correct position. (you did mark your spark plug wires didn't you? How else are you going to remember where they go?) Put the 2 hoses back on the air box, and your done!
This solved my problems with the low voltage, and my charge light or brake light hasn't came on since. It's nice to be able to spend an our or 2, and $10 in parts to save $200-$400 bucks that a shop would charge you to replace the alternator!
Total time was about 2 hours. This could be cut in half if you get the Toyota part.