Yes, I installed them all myself
Warrantee is only voided if the specific modification directly affected the part that broke.
So with that, If I would have had an electrical problem, it might have voided that portion of the warrantee, but installing gauges won't affect your engine, tranny, differential, etc.
.... unless of course you lost all your oil because of a poorly installed oil pressure/temp gauge. You see what I mean though.