I'm replacing an old 3 way light switch in a 1950 house. The old switch has four terminals, two white and two black. The new switch only has three terminals. How should I connect the new switch?

I can help u with this but will need to b able to walk u thru it,

Unplug the dryer then remove the terminal block cover and disconnect the 3-prong cord from the dryer. Note that the cord has red , black, and white wires but sometimes the red and black wires are both replaced by same color wire, usually gray and can switch places. There's also a ground strap wire also connected to the center terminal together with the white (neutral) wire.

Get yourself a 4-prong cord and note that it has red, black, white, and green/yellow wires but sometimes, like the 3-pronged one, the red and black wires are both replaced by same color wire, usually gray and can also switch places. All you have to do now is connect the 3 wires in the same manner they are connected as 3-prong cord to the terminal block. The ground strap wire now just need to be connected to the remaining 4th wire, the green/yellow wire instead of the center terminal together with the white (neutral) wire. Reinstall the terminal block cover and it's done.

It can be observed that converting a 3-prong cord to 4-prong cord is merely splitting the neutral line and the ground thereby increasing the number of prongs from 3 to 4 whereas, on the other hand, converting a 4-prong cord to 3-prong cord is merely joining the neutral line (white) and the ground (green/yellow) thereby reducing the number of prongs from 4 to 3.. The links below might enlighten you further on this matter.

Four-prong to Three-prong Electric Dryer Conversion
Three-prong to Four-prong Electric Dryer Conversion

1. Open the switch housing of the fan. This is usually achieved either by removing two screws on the bottom cap of the switch housing, or three screws on the side. Remove the pullchain assembly by unscrewing the brass finial on the outside of the switch housing.

2. Make careful note of which wires attach where to the pullchain. The chain itself will be marked L-1-2-3 or A-B-C-D or similar, the wires will customarily be of different colors, but if not, mark both the wires and pullchain if necessary. MAKE CAREFUL NOTE OF WHICH WIRES ATTACH WHERE. Every fan is different and if you do not make note there will likely be a complicated guessing game. I cannot stress this step enough. Make careful note of which wires attach where to the pullchain. For example:

Black - L, Grey - 1, Brown - 2, Purple - 3.

Some fans may use only two or three wires, some may have a pullchain with two layers and five or more wires. Regardless, make careful note of which wires attach where.

3. Remove the wires from the pullchain. In some cases they may be attached via wire nuts, in which case, remove the wire nuts. However in most fans the wires are inserted directly into the pullchain. Don't make the mistake of cutting them, they can be removed completely by inserting a very small flathead screwdriver into the slot next to each wire. You will notice the ends of the wires are soldered, this is so they will attach to the pullchain.

4. Determine the correct replacement pullchain. This is the tricky part. Many pullchains look alike but in fact switch differently. There are a few factors, first of all, how many speeds does the fan have as controlled by the pullchain? Second of all, how many wires are used to connect the pullchain? These will determine maybe 75% of replacement pullchains. Here are some examples:

- If the fan has three speeds and the pullchain has four wires, it is most commonly a L-1-2-3 pullchain. This is a single pole triple throw switch with an off position. It connects the power from L to 1, 2, or 3 respectively, one for each speed.

- If the fan has three speeds and the pullchain has three wires, it is an L-1-2-1+2 pullchain. This is a single pole double throw switch with an off position and a "both" position. That is to say, in connects power from L to 1 or 2 respectively, and on the third position connects to both. This is the same switch used in many lamps to switch on one bulb (or set of bulbs), the other, or both.

- If the fan has two speeds and the pullchain has three wires, it is most commonly a L-1-2 pullchain. This is a single pole double throw switch with an off position. It connects the power from L to 1 or 2 respectively.

- If the fan has three speeds and the pullchain has more than four wires, there are a handful of different pullchain possibilities however most hardware stores stock the most common replacement. This would customarily be a double pole switch with two layers of wires attaching.

The replacements mentioned above are the most common examples . . . but as I said, there are other switches that may appear identical (for example three speed fan, four wires, but it's NOT the first switch I mentioned). In most cases I would first try the replacement mentioned above. These are the switches that your local hardware store should stock. If the fan does not work with the likely replacement, does not work on all speeds, spins too fast, too slow, etc . . . and you are sure you properly noted which wire connected where on the old pullchain and wired the replacement correctly . . . then it appears your fan is in the 25% that uses a non-standard switch. There are three ways to determine the correct replacement switch:

- Contact the manufacturer. If they are still in business they can theoretically send you the correct replacement switch. If they are no longer in business, contact someone on our forums or other ceiling fan experts, we/they may be aware of the correct replacement for your particular model

- If you can still switch speeds on the old pullchain, use an ohm-meter to check for continuity between the various wires on the various positions. In most cases the important relationships are between L and the various other positions, for example a three speed four wire switch might be L-1-2+3-3. This means in the first position L connects to 1, in the second position L to 2 and 3, in the third position L to 3, fourth position off.

- If you can not operate the switch, you can open up it's plastic casing, either to operate the switch by hand, or to observe the metal bands inside. Some websites that sell replacement switches offer diagrams of the metal bands, by matching your switch up to the diagram you can determine the correct replacement.

5. Ok, you've determined and obtained the correct replacement switch.Seeing as you made careful note of which wires connect to where on the old switch, reconnect the wires in the same manner to the replacement switch. If your old switch did not require the tips of the wires be soldered you may need to do so in order to properly attach them to the pullchain.

6. Reattach the pullchain to the switch housing and replace the finial. Replace the switch housing cap with the two or three screws.

Additional Notes:

I. Fan lights where the pullchain is simply on/off use a two wire pullchain. This pullchain is a very standard on/off switch and it is simply connected to the two wires to which the old pullchain was connected. The wires can be reversed and it will still work. Lights where you can select one bulb, the other bulb, or both use the pullchain mentioned with that example above.

II. Some fans do not use the pullchain to control speeds, but instead have a dial or other control on the fan for speed selection. The pullchain is used to turn the fan off and on, and in some cases also to reverse the fan, select between the high speed and the various low speeds derived from the speed control, or also control the light. In these various examples:

- When the pullchain only switches the fan on and off, it most likely has only two wires and is equivalent to the light kit pullchain mentioned above. It is a basic on/off switch

- When the pullchain reverses the fan or switches the speed control in and out of the circuit, it is most likely the three wire two speed pullchain mentioned above. It is a L-1-2 switch. There are some exceptions such as certain model Fasco fans.

- When the pullchain controls both the fan and light, it is the three wire three speed pullchain mentioned above. It is a L-1-2-1+2 switch.

III. If for whatever reason you do not know which wires connect to which locations on the pullchain, you may yet have some options. For starters, black is almost always L. Some other common color combinations:

For many four wire pullchains:

L - Black, 1 - Grey, 2 - Brown, 3 - Purple
L - Orange, 1 - Black, 2 - Yellow, 3 - Purple
L - Black, 1 - Grey, 2 - Brown, 3 - Green
L - Grey, 1 - Yellow, 2 - Purple, 3 - Black
L - White, 1- Black, 2 - Blue, 3 - Yellow


For many three wire pullchains:

L - Black, 1 - Blue, 2 - Red

The correct way to wire this switch is the wire that was on the gold or dark colored screw of the old three way switch is called the shunt or common terminal. The wire connected to this terminal is to be connected to the black wire of the three way dimmer. The other two wires are connected to the silver or light colored terminals of the switch. These are the traveler terminals. The traveler wires may be connect to either traveler terminal - it does not matter which.

If you have already disconnected the old switch, simply connect the dimmer wires to the house wires as shown top to bottom in each configuration below until you get it to work as expected:


Config1 Config2 Config3

B R R B R R B R R Dimmer Wires: B = Black R= Red R = Red
R W B B R W W R B House Wires: R = Red W= White B= Black



In two configurations or less, you'll have found the correct wiring for the switch. I hope this helps & good luck! Please rate my reply. Thank you.

OK, your new switch will require the use of a neutral wire. So you will have to do what is called a pigtail. You will have to twist another white wire in with your other white wires to attach your neutrals to your switch. Note: white wires are called neutral not common. Hook the wires that were originally hooked up to your LINE to your HOT (Black) on your new timer, and the what was originally LOAD up to the new timer LOAD. SO as far as wiring all that will change is your white wires that need to attach to your timer NEUTRAL.

I can probably help you, but I need more info. Are you replacing a single switch that operated both of these lights together? Do you have 3 black wires and three white wires in the box now? Are the 3 white wires all connected together? Were 2 of the black wires connected to one terminal of the old switch, and 1 black wire connected to another terminal of the switch? ----- I'm doing lots of guessing here so that you understand the kind of info I need.

First, turn off the circuit breaker. The three wire bundle should be the incoming power, the four wire bundle should be going to the fixture. Using a duplex switch (one with two toggles), the incoming black wire goes to one side of the switch, the outgoing black and red wires go to separate terminals on the other side of the switch. The whites are connected together. The Grounds (or bare copper) are connected together and to the switch ground screw. Hopefully both the outgoing read and black were connected to the old switch or you may have to rewire the fan to wire up the fan and light separately.

Dryers come with a wire or metal strap connecting the center "neutral" terminal to the frame of the dryer. When using a four wire power cord, take that wire or strap off the frame. (it can be discarded or better yet, in case this dryer needs to ever be converted back to a three wire cord) connect the frame end of the wire / strap to the center terminal of the power block. Now, Green (ground) wire goes to the dryer frame, White (neutral) goes to the center terminal, and the Red and Black (both "hot") wires go to either outside terminal. (one to each)

The two terminal cap is only for the new fan motor. Connect the compressor wire back where you found it, on the 3 terminal cap. It's the terminal marked, "herm". The "common" terminal on the 3 terminal cap must still be connected to one side of the 220 power at the contactor. One side of the 220 goes to the common on the compressor. The other side of the 220 goes to the run winding on the compressor AND the common terminal on the 3 terminal capacitor.

Yes, these cords can easily be switched. When you remove the three prong cord from the terminal block in the rear of the unit, you will wire the four prong in the same way. Black and red go to the outside terminals, white to the middle terminal, and the green wire goes to the cabinet or ground screw on the outside (usually, there is a greenish looking bolt around the terminal block door area for this to go). The only difference in a 3 and 4 prong configuration is the extra ground (green) wire. Good luck and let me know if you need further information.