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REPAIRS PAGE 87

HEADLIGHT SWITCH REPAIR

I was recently experiencing some problems with the headlights on my '85. When I turned them on nothing happened! Anyway I pulled out the switch, cleaned it and now they work. Here are some notes you might find helpful:
part I getting to the switch

1) to get at the switch, you remove the instrument finish piece, there are 11 (!) screws that hold it in place. The black "button" on the top finish panel is a temp sensor or something - it does not hide a screw.

2) pull out the finish piece far enough to unplug the back of the switch. the assembly also contains the instrument light dimmer switch.

3) pull off the paddle on the front of the switch then use a deep socket to remove the fastener that holds the switch to the finish piece.

4) remove the switch then marvel at the felt lined interior panels on your MR2. Come back to earth.

Part II checking the switch

1) put the paddle back on the switch so that you can switch it easily.

2) you need some kind of continuity tester. if you don't have a multimeter (worth every penny) then you can make a tester with a battery, battery - holder, some wire, and a light bulb. there are also very inexpensive testers (made with the above materials) available at auto stores.

3) the back of the switch has a connector that looks something like:

           4 3 2 1
      ______________
     | - -   - - |
     | - - - - - |
     |______________|
       9 8 7 6 5

4) Turn the switch one click from off, this should be the parking light position. check for continuity of terminals 8 and 9.

5) Turn the switch on more click - the headlight on position. Check for continuity of terminals 9,8,7, and 4.

6) Push the switch in and turn one more click - the hold position. Check for continuity of terminals 9 and 7.

7) If any of the above continuity checks fail, you do not necessarily need to replace the switch

part III - tearing apart the switch

1) The back off the switch can be removed with a small screwdriver. be careful with the two wires that attach to the connector part.

2) Inside you should see a disk with some copper bits on it. clean the copper pieces as well as you can with some type of solvent. make sure the solvent does not harm the plastic though. On the connector side the is a board with some contact strips printed on, clean these with an appropriate solvent (if you are not too environmentaly concerned - use "Blue Shower") you might also test the continuity of the strips with the terminals on the back.

3) Put the assembly back together and re-test. If the switch still does not work, keep cleaning. Also check to see if the copper brushes are "springing."

4) If you become absolutely frustrated and can't figure out why such a simple switch still doesn't work THEN buy a new switch. However it will be worth your time if you buy one from a junk yard ( test the continuity after you pull it). The dealer here wants $5 billion for this switch.

Another note on junk yards - buy a bunch of stuff at the same time and haggle over the price. even if you don't need the extra junk now, you will probably get the whole lot for the price they would charge for a single piece.

part IV

1) Put everything back together, wait till twilight, and drive off into sunset -good luck

By Kurt Krueger (kurt.d.krueger@TEK.COM)

I need to give many thanks to the original poster of the detailed info on repairing the headlight switch ... I left the article at home so I don't have his name.

Some further info:

1. If you remove the dash light dimmer 'knob' it is possible to push the main shaft out of the switch. There's a spring and a detent ball in there. A pain to reassemble (assuming you don't lose the ball). If your dimmer 'knob' is cracked like mine, be careful.

2. After 2 thorough cleanings of the contacts, I still had intermittent operation of the headlights. One of the soldered plug pins was suspiciously slightly dull. Just a little dull. However, that turned out to be the culprit. After a resolder, the headlights started behaving. (Hope it continues...).

3. My circuit board had a lubricant on it. I opted not to remove the grease, but used a toothpick to make sure the metal under the contacts wasn't corroded. Anyone know what kind of grease they use on these things? Seemed kind of waxy ... like the grease you use on the rubbing block of your distributor points (remember those??)

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