MTX Thunder Form JWTJ97C20A-TN, Owner'S Manual, Page: 7 / 12

M T X . C O M
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Step 18 - Plug power wire harness into amplifier pre-amp.
Step 19 - Replace 20 amp fuse under hood.
Step 20 - When amp turns on, LED will display red during diagnostic mode, and then green, signaling
amp is on and functioning. Amp will only turn on when radio is on.
Step 21 - Adjust gain.
Setting Gain
Turn gain knob on ThunderForm pre-amp to minimum, counter clockwise. Play a favorite song that
contains consistent music and bass. Turn the source unit to maximum listening level. You should
know that some source units will produce distortion or “clip” before the unit reaches maximum
volume. Reduce volume to the loudest listening level before distortion. Turn the gain knob on the
ThunderForm pre-amp clockwise until the speaker starts to distort and reduce gain to loudest
listening level before distortion.
Optional - The EBC, or Electronic Bass Control, allows a remote bass control to be adjusted from the
driver’s seat.
Troubleshooting Tips if Amp Does Not Turn On
• Check all connections at battery and that fuse is installed
• Check speaker wire connections
• Check ground
• Check fuse on pre-amp
Step 22 - Check wire harness under driver side threshold to be sure it’s secure in its factory location
and replace the three screw clips.
Step 23 - Using the supplied hardware, secure the enclosure to floor of vehicle.