Scott McKelvey
12-25-2007, 07:43 PM
Figured I'd post the following and hopefully someone can learn from it and save themselves some time.
I had some trouble with instrument lights and the taillights, so after a little reading it sounded like it might be something w/ the switch. Turns out it was the fuse panel leading to the switch, but hopefully this info will help anyways.
For the sake of discussion, I'll divide the switch in half b/c of how power is distributed: terminals 5,4,3,2; and terminals 7,6,1 (see pictures). There is also the unnumbered terminal for the dome light, which is a separate circuit. Three terminals supply power to the switch: the Unnumbered terminal and Terminals 5 and 1.
Terminal 5 is HOT via the right side of the bottom fuse (THIS WAS THE PROBLEM b/c the left side of that fuse is HOT, but clip on the right side of the fuse was badly corroded and not making a good connection). Terminal 4 gets power from 5 when the switch is pulled out and goes to the rear lights. Terminal 3 is jumpered to 4, so it gets power too. Terminal 3 then goes to the outside part of the Dimmer rheostat (coiled wire). The rheostat then connects to Terminal 2 via a tab on the switch which rotates around the coiled wire as the knob is turned.
The other side of the switch receives constant power via Terminal 1. When the switch is pulled, terminal 7 is said to go to parking lights, but I don't know for sure. Terminal 6 reportedly goes to the Hi-beam switch on the floor, but I didn't test this either.
The third circuit is an unlabeled terminal which is HOT from the Dome light. It is connected to a copper tab that is grounded to the switch housing when the knob is turned fully counter clockwise. The switch housing must be grounded. NOTE*** the dome light has constant power, but does not work until the circuit is completed by grounding it via the headlight switch, or the pins in the door jams***.
This is the terminal side of the switch w/ the corresponding wire colors and terminal numbers (sorry, the text is hard to read).
http://inlinethumb37.webshots.com/35428/2799512590066277615S600x600Q85.jpg
This is the sliding portion inside the switch. There are springs under the copper tabs which press them against the brass on the underside of the switch (see next pic). It slides up/down, as pictured. The rod that the know is on inserts in the bottom (as pictured), and you can see the edge of the metal clip that holds it, for which the small spring loaded button on the metal half of the switch housing (not pictured).
http://inlinethumb55.webshots.com/34486/2477875690066277615S600x600Q85.jpg
This is the underside/inside of the switch, opposite the terminal side. I've labeled them as such. You can see the arm that grounds the dome light in the bottom of the picture (thats what I'm holding it by). The rheostat is the coiled wire w/in the brown plastic, which is not visible from this angle.
http://inlinethumb01.webshots.com/34560/2089072440066277615S600x600Q85.jpg
But like I said, my problem was corrosion on the clip in the fuse panel, nothing wrong with the switch.
I had some trouble with instrument lights and the taillights, so after a little reading it sounded like it might be something w/ the switch. Turns out it was the fuse panel leading to the switch, but hopefully this info will help anyways.
For the sake of discussion, I'll divide the switch in half b/c of how power is distributed: terminals 5,4,3,2; and terminals 7,6,1 (see pictures). There is also the unnumbered terminal for the dome light, which is a separate circuit. Three terminals supply power to the switch: the Unnumbered terminal and Terminals 5 and 1.
Terminal 5 is HOT via the right side of the bottom fuse (THIS WAS THE PROBLEM b/c the left side of that fuse is HOT, but clip on the right side of the fuse was badly corroded and not making a good connection). Terminal 4 gets power from 5 when the switch is pulled out and goes to the rear lights. Terminal 3 is jumpered to 4, so it gets power too. Terminal 3 then goes to the outside part of the Dimmer rheostat (coiled wire). The rheostat then connects to Terminal 2 via a tab on the switch which rotates around the coiled wire as the knob is turned.
The other side of the switch receives constant power via Terminal 1. When the switch is pulled, terminal 7 is said to go to parking lights, but I don't know for sure. Terminal 6 reportedly goes to the Hi-beam switch on the floor, but I didn't test this either.
The third circuit is an unlabeled terminal which is HOT from the Dome light. It is connected to a copper tab that is grounded to the switch housing when the knob is turned fully counter clockwise. The switch housing must be grounded. NOTE*** the dome light has constant power, but does not work until the circuit is completed by grounding it via the headlight switch, or the pins in the door jams***.
This is the terminal side of the switch w/ the corresponding wire colors and terminal numbers (sorry, the text is hard to read).
http://inlinethumb37.webshots.com/35428/2799512590066277615S600x600Q85.jpg
This is the sliding portion inside the switch. There are springs under the copper tabs which press them against the brass on the underside of the switch (see next pic). It slides up/down, as pictured. The rod that the know is on inserts in the bottom (as pictured), and you can see the edge of the metal clip that holds it, for which the small spring loaded button on the metal half of the switch housing (not pictured).
http://inlinethumb55.webshots.com/34486/2477875690066277615S600x600Q85.jpg
This is the underside/inside of the switch, opposite the terminal side. I've labeled them as such. You can see the arm that grounds the dome light in the bottom of the picture (thats what I'm holding it by). The rheostat is the coiled wire w/in the brown plastic, which is not visible from this angle.
http://inlinethumb01.webshots.com/34560/2089072440066277615S600x600Q85.jpg
But like I said, my problem was corrosion on the clip in the fuse panel, nothing wrong with the switch.