[WashingtonKevin]

For piggybacking from an existing fuse is all you need to do you could use something like this..
Amazon.com: Wirthco 30001 Fuse Tap Kits- Ato: Automotive

Regards,
Kevin

 

[silverfox]

Yes I suppose that would be my quickest way. Fairly clean and inexpensive, cheers.

 

[WashingtonKevin]

Any parts store should have a few different types of those on the shelf. (for LESS than $10)

If you are new to electrical work, remember, to tap on the downstream side of the fuse so that you get the benefit of it.
If you want to tap the upstream side of the fuse, you MUST add a separate fuse in your circuit. A lone gauge light bulb should be fine tacked on to an existing fuse.

If you are unsure which is the downstream side do this:

1. Remove the fuse.
2. Take your multimeter and set it on DC Volts.
3. Touch the black probe to ground. (some bare metal part of the truck)
4. Touch the red probe to each side of the fuse pocket.
5. One side will show battery voltage (12-13.2). The other will show 0 (zero).

The one that shows zero volts is the downstream one.
Regards,
Kevin