MARK1970":3tlq1jq7 said:
Coil tapping and coil splitting are two different things. Coil splitting cuts one coil out giving you the single coil sound. Coil tapping decreases the output of the whole pickup. I have an LTD with coil tapping. It did not sound like a single coil, so I figured the pickup did not split well. I did notice the hotness of the pickup did change. Volume wise it was the same. I later found out that it did not sound like a single coil because it was not a coil split.

I now have it coil split and I get a nice coil sound.
This is mostly correct... but seemed potentially confusing regarding coil tapping, so I thought I'd elaborate.
You're right about splitting - it's only done with humbuckers, and it basically just uses one of the coils.
Coil tapping (I borrowed the wording for this) usually only applies to a humbucking pickup, but it can also be available on some single coils. Think about it like this: a pickup is a long coil of wire wrapped around a core that is magnetic. Say you have a coil that has 8000 feet of windings. It would put out it maximum voltage (volume) at that full winding. Now, if the coil of wire had a wired soldered to it at the 4000 foot spot of the coil and that was connected to the output, the voltage (output) would be approx. half. It 'TAPS' the coil of wire at a shorter length. When talking about a humbucker, the term coil tapping and coil splitting are often used interchangeably, and sometimes that is accurate. If the humbucking pickup is tapped in the middle, then one of the two coils is circumvented so that the humbucking pickup is now a single coil pickup. On a Dimarzio, Duncan, etc. that has FOUR CONDUCTOR wiring, you can tap a humbucking pickup easily. There are two wires for each coil and they usually have one wire from each coil connected together and one from each going to the switch or volume control.
In addition, coil taps can be done at any point in the wiring. So you can tap your hot single coil pickup at 75% of the coil's wiring to give you a more vintage tone. Or your humbucker could be tapped at 40% so you are using only part of one coil.
A coil split is a tap. But a tap is not necessarily a split.