I bought a 1990 Ford F250 that came with the PowerStop installed. I pull a 2005 Cougar trailer. It's not applying any brakes that I can detect. The LED never comes on. Can't find a manual or schemo. Is this considered pretty old? Should I scrap it and put in a new one? Any recommendations on a good controller? I see a Reese Towpower 8507111 for about $60. Thanks!