I stumbled across this yesterday at Best Buy and did some research on it. This little 45wx4 amp from Alpine is designed to be used with specific Alpine head units and is a direct plug and play device. However, being the physical size that it is (7" x 2-1/2" x1-3/8"), it would make an awesome choice to replace that horrible audio output of the stock HD radio to something quite a bit cleaner. I searched and searched and finally found the wiring diagram for this thing so you can cut the molex plugs off and wire it up to any system. I did talk to Alpine about it and it will handle a 2 ohm load but it's not recommended. So for the cost of a good pair of 4 ohm speakers like the J&Ms and the $100 or so you'll pay for this amp you can get out fairly inexpensively. Below is the wiring color codes for the wires on both (input and output) harnesses. If you need wiring colors for your bike, feel free to holler at me and I'll do what I can.

On a side note; most of the kits you get from Hawg-Wired, Hogtunes, J&M, etc all come with some sort of bracketing system to keep the amp from sitting directly on top of the radio (metal to metal). There is a reason for that and it's called heat. I would never recommend you sit an amplifier directly on top of your radio because of this. If you need to mount it directly on top of the radio, go down to hobby lobby or some arts and crafts store and get you a few strips of something like 1/8" lead or the likes of it to put under the amp before you mount it to the top of the radio.

This is not meant to be anything other than an opinion for those of us who are wanting to upgrade sound but not spend a fortune doing so.


UltraNutZ


Alpine KTP-445 Wiring Colors

12V+ Constant - Yellow
12V+ Switched - Red
Ground - Black
Remote - Blue/White
Left Front Speaker Positive - White
Left Front Speaker Negative - White/Black
Right Front Speaker Positive - Gray
Right Front Speaker Negative - Gray/Black
Left Rear Speaker Positive - Green
Left Rear Speaker Negative - Green/Black
Right Rear Speaker Positive - Violet
Right Rear Speaker Negative - Violet/Black

 

I have this Amp working with the Stock HD Radio on a 03 Ultra, the Stock 8 Ohm Speakers were replaced with Polk Audio 4 Ohm 5 1/4". This alone makes a huge difference but it breaks up over 3/4 volume.







Take Your time, be sure to Mark everything and read through this before you begin. I used Insulated Spade Connectors but Solder and Shrink Tubing are a better way to Connect the Wires. Look at the Pictures

• The Alpine KTP-445 Amp has 2 connectors, the one with the Fuse (Yellow) is the Power in and Speaker Output, this seems backwards but if you think about it the Alpine Head unit Plug is the Power IN and Speaker OUT.
• If you don't have a Service Manual, write down the Speaker location and the Color of the Wires. Remove the Front of the Fairing and pull the Rear Speakers Out for Wire ID. The Smaller Terminal is (+)
• Mount the Amp on top of the Radio with an Air Gap. I used 1X1/4 foam Tape. See the Pictures.
• Cut the Connector Off of the Fused Side, Mark this Side of the AMP "Speaker Out" and the other side "Speaker In".
• Mark these Wires
• YELLOW W/ FUSE (+12VDC)
• BLACK GROUND
• BLUE/WHITE SWITCHED (+12VDC)
• Now using the list below mark the 8 Output to Speaker Wires
• Use Electrical Tape or Butt Connectors and Cover the Ends of the remaining Left Side Wires and tuck the out of the way.
• I started with the Right Front, pull the (+) wire off the Speaker and Mark it RF IN, I used Masking Tape and a Sharpie. Continue with the other Front Speaker Wires.
• The Amp Wire Colors are the same on both Connectors. You will only need 8 wires for the Speaker INPUTS on the Right Side of the Amp.
• Cut the Right side Connector Off then mark the wires.
• AMP COLORS---------------- ---------03 ULTRA COLORS
• Left Front Speaker (+) WHITE ---------WHT/ORANGE
• Left Front Speaker (-) WHITE/BLACK ---LITE GREEN/WHITE
• Right Front Speaker (+) GRAY ----------GRAY/RED
• Right Front Speaker (-) GRAY/BLACK ----LITE GREEN/BLACK
• Left Rear Speaker (+) GREEN -----------BROWN
• Left Rear Speaker (+) GREEN/BLACK ----WHITE/BROWN
• Right Rear Speaker (+) VIOLET ---------GREEN
• Right Rear Speaker (-) VIOLET BLACK ---LITE GREEN/BROWN
• Tape (electrical) the Ends of the Unused Wires on the Right Side and tuck them out of the way.
• Start connecting the Amps Right Side Wires to the Wires you pulled off the Front Speakers. No need to cut the Stock Harness for the Front Speakers.
• My Radio has 2 large Connectors on the Back of it.(Looking at the back) The Rear Speaker Wires are on the Lower Right Connector. carefully cut about 2" of the Outer Sleeve and fold it down.
• Locate the 4 Wires that match the Rear Speakers.
• Cut these 4 Wires about 2" down from the Connector.
• The Short Wires coming Out of the Radio Connector are the Amp Inputs.
• Connect the 4 Right Side Amp Wires to these.
• The Amp Inputs are now done.
• Connect the 4 Wires on the Left Side of the Amp Directly to the Front Speakers and then the 4 others to the Lower Radio Harness, these go to the Rear Speakers.
• Now for the Power.
• Temporarily Pull the Fuse Out of the Yellow Wires holder.
• I ran a Wire from the Battery (+) under the Tank to this Yellow Wire. Position the Fuse Holder under and in back of the Fairing so you can access it.
• The Black Wire runs down to the Ground Screw on the Frame (just in front of the Tank on the Right side).
• If Your bike has 2 extra Wires on the Headlight Harness connect the Amps BLUE/WHITE Wire to the ORANGE/WHITE Harness Wire. If it doesn’t have this you will have to find a Wire that is Switched ON in RUN and ACCESSORY and connect it to that.
• Check all the connections for correct Color and Polarity.
• ReInstall the Fuse (YELLOW WIRE)
• Turn Your Key to ACC and turn the Radio ON it should be much Crisper and Louder than before.
• Cool You did it!
• Ty-Wrap the Wires and secure the Amp.
• ReAssemble the Fairing and enjoy

This should work for any 4 Channel Radio on anything.
**Classic disclaimer**This is just my opinion..I have NO responsibility, or liability for your bike tunes.
EZ GLIDER

 

I just saw your post while working on installing this amp in my Ultra. Your pictures indicate the speakers are hooked up to the wires from the connector on the right. I could not find color matching wires for the front there. Looks like the front color is in the harness to the left. Hope you can help???

 

The speakers are hooked up from the connectors from the left side of the amp.

The Stock Front Speaker Wires (from the existing Radio) are disconnected from the Speakers and are now the inputs to the Right Side of the Amp.

The Left Side Amp Wires then go directly to the Speakers.

You are basically taking the connection from the radio off the speakers, re-routing it thru the amp, and back to the speakers.

 

From your pics what was wired to right side of head unit. On my Ultra the front speaker wires match output from left side of head unit and the rear wire colors match wires on output of right side of head unit. Second what do I do with the red wire. I have yellow routed back to battery, black grounded to ground terminal under fairing and the blue/white hooked into orange/white wire from headlight.

 

seen this unit and was also curious, i have the same speakers on my 2000 ultra, how are the results? Is it worth the money? Where did you put it? I want the rockford but don't have the money right now.

Thanks Tom

 

You are correct, the Front Speaker Wires are on the Left Side Radio Connector but you don't have to cut into the harness as these Wires are already on the Speakers. Pull these off the Speakers and connect them to the Right Side of the Amp (INPUT) then the Left Side of the Amp Wires (OUTPUT) get connected to the Front Speakers. I hope this helps.

 

Tom, I feel it is worth the money, see the pictures for the mounting, the connections should be similar.

mnorris, the Red wire is not needed, Tape it off.

 

Ez are the rear wires the ones coming out of the upper right of head unit(white connector). I assume I would cut them and splice in amp.

 

If You are sitting on the bike the Upper Right Connector on the Radio is for the Front Speakers and is not cut. My instructions assumed you were standing at the front of the bike and looking at the back of the Radio. The Rear Speakers are on the lower right Connector when looking at the back of the Radio. This is the one you need to cut & splice. EZ