Exterior Yellowing

I suppose it could be the wax turning yellow. If so, does anyone know how to remove old wax and return my Bighorn to it's original white?

You didn't tell us how old your FW is and what is yellowing - Trim/plastic molding/cap/sidewalls, or what the material is. It helps if we know so we can help you, sometimes while removing mold from my old RV I used Soft Scrub on some of the plastic and trim and everything whitened right up, but if you read the small print it has bleach in it so you really have to be careful around the decals etc. and get it right off with lots of clear water.

It is mostly yellow on the trim around the slides but generally the siding has turned. The FW is a 2008. We had the RV in the factory for frame repairs and they replaced some of the siding and the difference is very noticable.

I'd do a search on the forum, (exterior polish), (Exterior Cleaner) (Gelcoat Polish) (Filon Cleaner) and maybe something will turn up which will help you.