1. Remove power and antenna.
2. Remove screws open case.
3. Locate the Logic Unit. It is located under the PA unit, (the PA unit has the speaker in it.) Follow the instruction used when installing the UT-34 Tone Squelch unit.
4. Attach two diodes as shown, (any standard diode) D10 to 3rd pin & R49 to D15
5. Reassemble the radio.
6. Reset the microprocessor (Press and hold [M-CL] and turn power on)