My wire broke in my attempt to pull the new wire thru the trailer (with the old one). What would you guys use thats stiff enough (and flexible enough) to run a wire thru the trailer?

electricians use a "snake" that will work great.....basically 50 ft of rigid spooled "wire" that you can force through the trailer, attach wires and pull back out. Home Depot, etc sell them.

I agree. A snake would be the next best bet.

Its called a fish tape, in case you go to the store and ask them. Usually its in the telecom/data product area.

I picked up a 25 foot snake at home depot for $10 and it worked like a charm! Thanks guys!

I use the inner core wire from the shifter control cables. Works great and they're free if you have an old one laying around.