I just finished fixing my headlight switch and it's nice to have properly working headlights. This isn't a real easy job and if you haven't done much soldering in the past, I wouldn't recommend taking this project on. You'd be much better playing it safe and grabbing a switch from Icemark (http://www.mazdamark.com/switches.htm). If you're confident in your abilities, don't stop reading and hopefully you'll have a like-new switch in the end.

I'm not going into the details of removing the switch from the gauge surround. If you have a bit of trouble, try taking out the turn signal module.

This should be exactly the same for both S4 and S5 switches.

Here's the list of supplies you will need:

- Soldering iron ($2 unit I purchased off the clearance table at the local H/w store. 8w, decently small tip)
- Solder (.032 dia., 2.5oz 60/40 mix from Radio Shack, $5 for the spool)
- Solder sucking vacuum ($7 from Radio Shack, but this one kinda sucks, try and find a better unit)
- Contact cleaner ($6 from Pep Boys, QD brand)
- White lithium grease or some type of sticky lubricant
- 200 grit sandpaper
- Vasoline
- Misc. screwdrivers and highly recommend a trim pulling pry
- Sharpie marker
- Multimeter

Ok, here's the step-by-step:

1.) Move all switches to their lowest position, then remove all the ***** from the unit. They should all just pop-off when you pull on them. Some might require a small amount of prying.

2.) Pull the plate that covers the main PCB by gently prying as shown:



3.) Flip the switch over, then remove the solder from the circled point by heating it up with your iron, then sucking it out with the vacuum tool. Be careful not to burn the PCB or apply too much heat.



4.) Flip it over again, then remove the solder from the points circled below (try not to burn the surrounding plastic like my dumb *** did):



5.) Flip the unit over once more, and carefully seperate the brown board from the switch body. If you removed all the solder, it should come out with little effort (you just have to click it out of the tabs holding it in). If it doesn't, get an assistant to heat the points up and pry them out one at a time. Be very careful if you have to do this, you run the risk of cracking the PCB or destroying a trace (sorry, no pics, hands were too busy.) Also beware of the black piece of plastic below. It can pop out at you and you do not want to lose it's inards.

6.) Use your sharpie to mark the position of the white turning piece on the bottom side in relation to the board. It is important that it remains in the same position during re-installation. If your dimmer **** is malfunctioning, check the traces on this board, and you may want to remove the white piece and check the contacts below. Mine where black, but I think it's normal. Just check for corrosion or sooty build-up and remove it as necessary. Sanding the are and cleaning it up with vasoline works well.

7.) You can now remove the black plastic deal nestled in the cavity. When doing so, use the prying tool in one hand, and with your other, cover the are that is circled with your finger while you pry it out. There is a spring with a ball bearing in there that will shoot out if you don't hold it in.



8.) Now you are free to remove the white plastic insert. Prying in the order the points are numbered seems to work best, but be very careful of the thin prying points 3, 4, and 5.



9.) Flip the unit over again and remove the solder from the rest of the points in that back "row" on the PCB.

10.) You should now be able to pry the switch plate itself out from the back-side (the one you pulled the white insert from). Again, be carful because the side of the switchYou may need to resort to the heat and pull method mention in step 5.

 

11.) Your plate will probably be pretty ugly, something like the picture below. To clean it up, just use your sandpaper to remove the corrosion, the spry them off with the contact cleaner and use a little bit of vasoline on a piece of paper towel or cloth to clean the dust and residue off of the plate. Don't leave gobs on there, but a thin layer is ok.



12.) Now remove the rotating assembly from the body. Carefully pry around the edges, and like the dimmer insert, be very careful of the circled area. It also has a spring and a ball bearing that will jump out and get lost if you're not careful.

13.) Remove the copper brushes from the rotating assembly. Be careful of the springs that hold them in, and try to keep them bent in the same shape (they should be bent slightly towards each other to grab the catches in the assembly itself). Sand the tips down, and spray them down with contact cleaner to remove any corrosion and residue. After cleaning, wipe them down with the vasoline and leave a very thin layer on them.

At this time, you can remove the entire PCB if you wish. The points that you need to remove are as follows:



I would only recommend this if you suspect a bad trace or cold solder joints. I did it when I rebuilt this switch just to check things out, and found no real problems. A good spray down with contact cleaner may be a good idea to clear and residues or corrosion from the joints.

Now you can begin re-assembly.

1.) Pull the springs for the brushes out a little bit, then but a bit of grease on the tip, and insert it into the assembly while twisting. Push the brush into the assembly, makeing sure that the little point on the bottom goes into the spring, and that the brush snaps in and doesn't fly out. Push the spring a couple of times to make sure it doesn't stick.

2.) Lube up the chamber that the rotating assembly sits in, then pull the spring for the rotating assembly out a slight bit, then put a bit of grease on the tip, and insert that tip into the assembly while twisting to spread the lubrication. Push the ball into the assembly on top of the spring, and carefully put the whole unit back into the switch body. Be careful not to lose control of the ball and spring, and rotate the assembly to the full down position that it was in when you removed it. Push it in gently to make sure it's fully seated.

3.) Use your soldering iron to spread any remaing solder on the "spikes."

4.) Push the back plate back in, making sure it is properly seated.

5.) Push the white insert back in behind the back plate and make sure it snaps into place on all sides.

6.) Put a chunk of lube on the spring for the dimmer rotating thing, push it into the black piece and put the ball in after the spring, then push it back into it's place in the white insert, making sure that it's in the lowest position.

7.) Clean the spikes on the brown PCB so that they will slip through the plastic insert and PCB on the other side.

8.) Carefully push the spikes through the insert, then push the rest of the PCB down into the insert, makeing sure the spike coming up from the switch back plate goes through it as well. Also make sure the the white rotating piece on the underside matches up with the black dimmer rotating insert and it's aligned correctly (by using your sharpie mark from earlier)

9.) Solder the little spike on the brown PCB back in place.

 

Only thing I would add:

If you pull out the PCB (as mentioned at the end of the dis-assembly stage) and have a 86-87 switch with a clear cased relay, you want to replace that with a new sealed relay. The relay is the same relay used in the wiper switches and can be found on my webstore (relay1 http://www.mazdamark.com/prod01.htm) or at digikey.

This will fix a bad retractor circuit if the headlights do not always go up or down and the switch is found to be the problem (not the motors).

If you have a 88-92 version the relay is already a heavy duty version (and the case of the relay itself is not clear).

Of course is the previous owner burnt out the switch, then you could have the 86-87 version in a 88-92 car and not know it.

The switch that uRizen has taken apart above is an older 86-87 switch that I normally would replace the relay in on my rebuilt versions.