2009 Ford E450 transit bus, tricked out by Eldorado National. Ext. heated mirror controls, anyone know how they work? No markings on them.?

PS.........I've tried looking online for manual, but can only find people trying to sell their own transit buses.

There's center on/off rocker switch between 2 knobs, but no markings on knobs to show different switch positions. Might refer to high/low settings or maybe refer to top and bottom mirrors not sure. Thanks for any help.

Try calling the bus co and seeing if they can tell you or fax a picture.................http://ks.enconline.com/contact_us.aspx