I just got 2 small led strips and I want to have them on whenever the car is running so i wrapped one end to a constant fuse and grounded the other. When I started up the car the lights were super dim, you could barely see them. What could be the problem not enough power or something? I merged it to the 10 Amp radio fuse.

 

You got LED strips without a control box? just cause its a ten amp fuse doesn't mean it putting out ten amps. What is the recommended voltage and wattage for the LED strip (wattage is P=IxE, P=wattage, I=current [in amps] E=Voltage) If its dim your probably running the wrong Amperage through the LED strips. Could also have a bad ground. check the suggested rating on something before you just plug it in. could also be a cheaply doped LED's are they SMD LED's or standard?