I am putting two ken wood kca-rc60mr's in a boat along with a ken wood kmr-440u. The one remote (which is the farthest away from the head unit) will not work and by hooking it up it brings the second one down also. I shortened the wire runs and upgraded the signal wire. Still does not work. Power to both remotes is good. Is there such a thing as an inline signal booster?

 

If you have the two connected right close to the deck to they work together?

The manual has no warning about maximum cable length so you might need to contact Kenwood.