This is the series of posts that covers the issue pretty well:
Recently installed new leather with heated seat elements. Here is my video review of the leather and quick look at heated seat switches This information is for a 1997 FZJ80, I am not sure if all models have the factory plugs under the center console, please check to verify. PREFACE The truck...
forum.ih8mud.com
I plan to mount the switches in the otherwise useless coin slots in the center console which may be a trick as I currently have that area full of thinsulate scraps.
The precise wiring into the connectors is in page BE-101 of post #8 above.