Improve the Audio Quality of Your Factory Harley Radio

Factory Harley radioA great way to improve the audio quality of ‘14 & up Harley radios is to add load resistors to all four of the speaker outputs of the radio. This dramatically decreases distortion when the radio is connected to an amplifier instead of being connected directly to the speakers. We sell plug and play connectors with load resistors already in line with RCAs, but you can also make your own. 

You can find our pre-made plug & play adapters for front and rear here. 

Don't Skip this Step!

An important step that many people miss is not putting resistors on the rear speaker output of the radio. Even if you do not use the rear speaker output, you must add load resistors in order to keep the radio from distorting.

How It's Done

You will need a 10 watt 47 ohm resistor for each channel (one for left and one for right, both front and rear). Solder the two resistors between the positive and the negative wires of the rear speaker output plug. Make sure that the connections are well insulated.

47 ohm load resistor

The rear speaker output plug can be located behind the radio. The front speaker output plugs are located on the sides of each fairing speaker enclosure.

Harley rear speaker output plug

It will be an unpopulated 4 pin connector with a rubber cap. You will want your resistors to be connected to pins 1 & 2 as well as between 3 & 4 as shown below.

Harley rear speaker output plug with pin out


I prefer to solder a length of wire to both sides of the resistors, fold one side over, and then heat shrink the assembly. Then the pigtail wires you are left with can be spliced into the rear speaker output harness. The resistors have no polarity, so it does not matter which end of the resistor goes to a positive or negative speaker wire.

load resistor construction

More important information

Adding load resistors will reduce the strain put on the radio's internal amplifier. This will improve sound quality and the usable range of the volume control.

What It's Not 

  • Not a substitute for a proper radio flash
  • Not a high to low converter. This is still speaker level signal
  • Does not address the radio's equalization curve 

 Load resistors should be added in conjunction with the proper radio flash and ideally with a sound processor like the Arc PSM or the Audison Bit Ten.

 We have a more in depth article explaining how to properly integrate with your '14 & up Harley radio that includes information about flashing your bike and adding a sound processor you can find here.


Check out the links below to learn more about American Hard Bag products.


Plug & play UltimateHarnessCombo