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Discussion Starter · #1 · (Edited)
The heater switch for my 1988 Spider needed to be replaced, so I purchased a new unit, but discovered it was just a little bit different in size (not the problem). It came with instructions to take the existing five (5) wires and somehow magically use only four (4) wires, with no real explanation on which wires were to go to which terminals on the new switch.

I've attached photos of the old and new switch and the wires that are in the plug. There are two (2) Pink/Black, two (2) Yellow/Black and one (1) Yellow.

Can anybody explain how to wire up the new switch that shows only four (4) connectors?
 

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Hello Shadow14,

Thank you for providing the most excellent photographs. First I will tell you what I believe is being shown in each of your photographs, and then I will try and help you figure out how to wire the new switch:

Photo 1: I'm pretty sure this is your new/replacement switch, but I haven't a clue as to what the handwritten notes are referring to.

Photo 2: The base of the original 1988 heater fan switch, showing connectors 1 thru 5 from left to right. Note that connector 5 on the stock switch is cut off, since it is not used.

Photo 3: The plug coming out of the console that connects to the switch, with terminal 1 shown at the bottom in this picture. Note that although there are 5 slots for spade connectors in this plug housing, positions 2 and 5 do not contain any spade terminals. That's because those positions are not used/not required to make the two speed fan motor function.

Photo 4: The back side of the switch connector plug, still with position 1 at bottom, showing 2 Yellow/Black wires in slot 1, nothing in slot 2, 2 Pink wires in position 3, a solid Yellow wire in slot 4, and nothing in slot 5.

Now here's where each of the plug wires goes to (or comes from):

Position 1 (2 Yellow/Black wires): One of these Yellow/Black wires goes to the instrument cluster to light up the little fan light. It goes to Terminal 6 of cluster connector A (brown plug). The other Yellow/Black wire (that shares the same spade terminal in slot 1 of the fan switch plug) goes to the fan motor. Both of these Yellow/Black wires become hot (carry "juice") after the switch is changed/moved from the "off" position.

Position 2: No wires/not used.

Position 3 (2 Pink wires): One of these Pink wires brings 12V from Fuse #7. This terminal should be "hot" when the ignition is on. The other pink wire simply continues on to supply the same 12 volts to the digital clock (BORG?).

Position 4 (1 solid Yellow wire): This wire also goes to the fan motor (like one of the Yellow/Black wires) but this solid Yellow wire carries juice when the switch is moved to the "high" speed position, to activate the high speed function on the fan motor.

Position 5: No wires/not used.

So that's how the stock/OEM switch is wired. Now you will need to check the continuity between the 4 terminal lugs on your new switch whilst the paddle (or rocker) is in various positions, to determine where to place the existing wires.

Be aware that on the stock fan switch plug (shown in your photos 3 and 4), the metal spade connectors are only held in the plastic plug housing by a little metal tab that extends up off the spade terminal itself. If you can determine which side of the spade terminal the locking tab extends from, you can insert a very tiny screwdriver in from the open side of the plug to compress the tab and pull the terminal out the back, That way you may not have to cut and splice wires. You might be able to simply put the spade connectors (once extracted from the stock plug housing) onto the proper tabs of your new switch.
 

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Discussion Starter · #3 ·
Hello Shadow14,

Thank you for providing the most excellent photographs. First I will tell you what I believe is being shown in each of your photographs, and then I will try and help you figure out how to wire the new switch:

Photo 1: I'm pretty sure this is your new/replacement switch, but I haven't a clue as to what the handwritten notes are referring to.

Photo 2: The base of the original 1988 heater fan switch, showing connectors 1 thru 5 from left to right. Note that connector 5 on the stock switch is cut off, since it is not used.

Photo 3: The plug coming out of the console that connects to the switch, with terminal 1 shown at the bottom in this picture. Note that although there are 5 slots for spade connectors in this plug housing, positions 2 and 5 do not contain any spade terminals. That's because those positions are not used/not required to make the two speed fan motor function.

Photo 4: The back side of the switch connector plug, still with position 1 at bottom, showing 2 Yellow/Black wires in slot 1, nothing in slot 2, 2 Pink wires in position 3, a solid Yellow wire in slot 4, and nothing in slot 5.

Now here's where each of the plug wires goes to (or comes from):

Position 1 (2 Yellow/Black wires): One of these Yellow/Black wires goes to the instrument cluster to light up the little fan light. It goes to Terminal 6 of cluster connector A (brown plug). The other Yellow/Black wire (that shares the same spade terminal in slot 1 of the fan switch plug) goes to the fan motor. Both of these Yellow/Black wires become hot (carry "juice") after the switch is changed/moved from the "off" position.

Position 2: No wires/not used.

Position 3 (2 Pink wires): One of these Pink wires brings 12V from Fuse #7. This terminal should be "hot" when the ignition is on. The other pink wire simply continues on to supply the same 12 volts to the digital clock (BORG?).

Position 4 (1 solid Yellow wire): This wire also goes to the fan motor (like one of the Yellow/Black wires) but this solid Yellow wire carries juice when the switch is moved to the "high" speed position, to activate the high speed function on the fan motor.

Position 5: No wires/not used.

So that's how the stock/OEM switch is wired. Now you will need to check the continuity between the 4 terminal lugs on your new switch whilst the paddle (or rocker) is in various positions, to determine where to place the existing wires.

Be aware that on the stock fan switch plug (shown in your photos 3 and 4), the metal spade connectors are only held in the plastic plug housing by a little metal tab that extends up off the spade terminal itself. If you can determine which side of the spade terminal the locking tab extends from, you can insert a very tiny screwdriver in from the open side of the plug to compress the tab and pull the terminal out the back, That way you may not have to cut and splice wires. You might be able to simply put the spade connectors (once extracted from the stock plug housing) onto the proper tabs of your new switch.
Thanks, I've been going nuts, which seems to be normal for me these days, and will try to see how it all works out. I have the electrical diagram from PapaJam, but wasn't sure and don't want to cut any wire if I don't have to.
 

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Hi Shadow14,

The picture below shows what the female spade terminals inside the plug housing look like (without a wire attached). Notice the small tab that extends off the flat side. That's what holds the metal terminal inside the plug housing, and that's what you need to depress with a small screwdriver from the front of the plug (while pulling gently on the corresponding wire extending out the back of the plug) to extract the whole terminal out the back of the housing.

You may have to twist or push the screwdriver just right to get the terminal tab depressed enough, or pull up or down on the wire while tugging on it to get the terminal to finally release, but once you get the hang of it, it's pretty easy.

Then all you need to do is figure out which spade terminal goes on which tab on your new switch and shove them into place.

Good luck,
 

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