hello welcome to the site
the 05 mdx's did not have very much HFL issues.
the first thing i would be looking at is the phone. about 99% of the time the phone is the issue.
how old is the phone ?
did you make sure to put the phone to discover ?
im the phone guru at my dealership so i work with all of the phones .
well the list price on a new on is around 698.00 plus about .5 labor to install.
this is something you can install your self if your handy with a screwdriver and a socket wrench.
the HFL is located in the come light console where the map lights are.
so 1000.00 does seem high.
you can also buy this online from