I installed line outputs on my stock Delco AM/FM stereo Radio in my 71 El Camino, but I am concerned about leaving the amplifier output unloaded (10 ohms). I believe the output transistors may fry without the 10 ohm load. What should I use ? I have already put 12 watt/10 ohm non inductor wirewound resistors across the outputs but they get very hot. My line level outputs do work. Any ideas ?