You can make it a bench job, which requires removing the alternator from the car (jack up car, remove fender liner, undo serp belt, remove alternator, take to bench, etc.)
You can go in from the bottom, which seems to me, not having tried it, as a whole lot of work you don't need to do, not to mention damn near impossible and you have to do a lot of the stuff from the top anyway.
Or you can go in from the top. This seems to be what most people recommend and is what I detail here. It's not hard, but it is awkward and you have to work blind in a couple of places. I couldn't find more than the most basic procedure to follow, so I just went at it. This first time, knowing nothing and having to figure it all out as I went, took a good two hours or so. I could go in now in about 30-45 minutes. And you can, too. Here's how:
• Adjustable wrench (or whatever you prefer to disconnect the ground cable on your battery)
• 3/8" drive ratchet
• 3" extension
• 10mm deep socket
• 8 mm socket
• 13mm socket
• 14" drive ratchet
• 1/4" socket for 1/4" ratchet
• 2 Phillips bits --1/4" hex type
• A couple of 8" to 10" flat edge screwdrivers
• A flashlight that you can get into tight places
• A stubby flat edge screwdriver (may be optional)
• Telescoping magnetic "pick up" tool (optional)
Here's how you use them:
1. Disconnect the ground for the battery.
2. The alternator is located on the right side of the engine compartment below the end of the intake manifold.
3. Undo the two 10mm bolts that hold the oil fill tube.
4. Ari (who posts here) likes to tie it out of way. I just left it loose. Either way, it gives you a bit extra room to work if it's not bolted down.
5. There are several hoses and wires behind and under the intake manifold that get in your way on this job. Ari suggests tying them out of the way. I just pulled off some of the hoses and tucked others out of the way or worked around them. Do what works for you, just remember where they go.
6. Disconnect the electrical connection to the MAP sensor on the firewall and tuck it out of the way. You don't want to risk damaging the connector/wires and it makes it a little easier to work, and get your arms where they need to go.
7. Underneath the intake manifold there is a metal bracket that has a couple of small wire bundles attached to it along with a flexible hose that comes out of the false bulkhead. You have to unbolt this bracket so you can get the back cover of the alternator off. It is held on with two 10 mm bolts, for which you'll need the 3" extension. You'll have to find them by feel. I used a deep socket and the extension for this. You have to work blind and be careful not to drop the bolts. They shouldn't be on very tight.
Now it's time to go after the alternator
8. Looking down on the alternator there's a metal housing with a black plastic cover on its back side, facing the center of the car. Part of it is under the end of the intake manifold, a fact you will soon not appreciate.
9. There are two wires connected to the alternator, a large one and a thin one (which is green and white on my '96). The red one is held on by a 13mm nut. Use the 13 mm socket to remove it. Take off the nut and washer, bend the wire out of the way. Use the 8 mm socket for the thin wire.
10. There are three small Phillips screws on the back cover of the alternator. You can't use a screwdriver very well because the various wires and hoses limit your ability to do much. So get out the 1/4" driver ratchet and 1/4" socket. Fit a pointy, smallish Phillips hex bit to the socket and use that to loosen the screws. For this I used a stubby 1/4" ratchet that has the socket drive on one side of the head and a hex drive on the other side that takes a standard hex drive bit. I got it at Advanced Auto some time ago for a few bucks and it's a lifesaver on this job. However, If even one of the screws won't come out you'll have to pull the alternator and do the job on the bench. You probably want to avoid this. I had to put the wrench and bit on the bottom screw and tap it a few times with a wrench to break it loose.
11. Undo the screws and try really hard not to drop them. If you're lucky, they will wind up on the subframe and be awkward to retrieve. If you're not, happy hunting!
12. With the screws out of the way you now have to remove the cover, which is further held on with three plastic tabs that are (like most plastic tabs) prime candidates for breaking off. One is underneath the alternator, the other on the top toward the back of the car and the other is on the top but toward the front. This front one lives under the end of the intake manifold and is hard to get at. You need to release all three, then pry up the edge of the cover and work it loose. It's not hard, but it takes some fiddling...
13. The flat edge screwdrivers come in handy to pry up the tab under the end of the manifold and work the cover off, sort of all at the same time. Once the tabs are dealt with, try twisting one of the screwdrivers between the bottom edge of the cover and the alternator. It'll come loose.
14. If you do like I did and break the top of the tab on the bottom one, the stubby flat screwdriver can be used to work the bottom tab loose. You work blind, but you can stick the blade into the slot at the side of the tab and pry it up enough to get the cover loose.
15. Once you get the cover loose, you realize why you had to remove that bracket under the manifold: it blocks the cover from coming off the alternator. So using all three of your hands, hold the bracket out of the way and work the cover off. Again, not hard, just a bit awkward.
16. With the cover off, the voltage regulator (Remember? That's the point of all this!) is staring you in the face. Get the 1/4" ratchet and Phillips head bit out again and remove the two screws that hold the VR in place. These screws are bigger than the ones that held on the plastic cover, so use a larger bit. The screws are about an inch and a half long.
17. Pull out the old VR and notice how short the brushes are compared to the new one. Look at the shaft on the alternator and you'll see where the brushes ride against it. If it's like mine the brushes are wearing a groove in the shaft, so you may decide you need to replace the alternator anyway. Groan. Sigh.
18. The new VR will only go in one way, so put it in and tighten up the screws. Just snug them down good.
19. When you look at the back of the cover you'll be annoyed that Bosch didn't put a little door or removable cover panel to make it easy to replace the VR. It would have been simple to do and this job would be a lot easier.
20. Work the back cover into place using all three hands while keeping the bracket and assorted hoses and wires out of the way. Since the studs for the two electrical connections go through the cover it will only go on one way.
21. Reattach the three small Phillips screws first, then the two electrical connections.
22. Reattach the bracket to the manifold.
23. Put any hoses and wires back where they belong and reattach the oil filler pipe.
24. Reconnect the MAP sensor if you undid it.
25. Reconnect the ground cable to the battery.
26. Fire up the engine and you're good to go. Reset your radio stations and the settings for the EDU so they are in your preferred format (American, Metric, etc.).
Hope this helps. If you see anything that needs changing or have a better approach, click on my name and email me the change. I'll update and re-post. Scott will put this in the FAQ for future reference.
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