MTX Thunderform JEEP GRAND CHEROKEE User Manual

JEEP GRAND CHEROKEE

Warranty Statement

ThunderForm Loaded Enclosures purchased in the United States from an authorized MTX dealer
are guaranteed against defects in material and workmanship for a period of two years from the date
purchased by the end user, and limited to the original retail purchaser of the product.

Amplified ThunderForm Enclosures purchased in the United States from an authorized MTX dealer
are guaranteed against defects in material and workmanship for a period of one year from the date
purchased by the end user, and limited to the original retail purchaser of the product.

Product found to be defective during that period will be repaired or replaced by MTX at no charge.
This warranty is void if it is determined that unauthorized parties have attempted repairs or altera

­tions of any nature. Warranty does not extend to cosmetics or finish. Before presuming a defect is
present in the product, be certain that all related equipment and wiring is functioning properly. MTX
disclaims any liability for other incurred damages resulting from product defects. Any expenses
incurred in the removal and reinstallation of products are not covered by this warranty. MTX's total
liability will not exceed the purchase price of the product. If a defect is present, your authorized MTX
dealer may be able to effect repairs.

Proof of purchase is required when requesting service, so please retain your sales receipt and take

a moment to register your product online at www.mtx.com.

21A7257

Vehicle Specific Subwoofer Enclosure

Made in the USA

One Mitek Plaza, Winslow, IL. 61089

1-800-225-5689 www.mtx.com

READ ALL DIRECTIONS CAREFULLY BEFORE BEGINNING

MOUNTING LOCATION: The enclosure mounts firing to the center of the
vehicle behind the factory spare tire of 1993-1998 Jeep Grand Cherokee,
except optional aluminum spare that was most predominant in 1996-1997
model years.

TOOLS REQUIRED FOR INSTALLATION:

Wire Cutters Phillips Head Screwdriver
Terminal Crimpers 7/16” Nut Driver

INSTALLATION: Follow the steps below

1. Remove the spare tire. Unzip the cover. Remove wing nut and washer

holding spare tire. Place enclosure in location occupied by spare tire.

2. If externally amplified make speaker connections to the enclosure
from the amplifier; loosen terminal knobs (a 13-mm nut driver can be
used). Connect speaker wires from amplifier to enclosure, positive to red
terminal knob and negative to black terminal knob. Refer to Step 19 for
mounting directions.

AMPLIFIED THUNDERFORM

Routing Power Wire; we recommend a connection directly to the
battery.

3. Remove driver side threshold trim; remove the phillips head screws

and pull up on trim, it will remove easily.

20. Install grill pegs provided into holes in the back of the grill. Start pegs
into the holes using a 7/16” nut driver over peg and push until base of peg
is flush with the grill back. Push grill onto enclosure, lining up the holes on
the enclosure with the pegs and firmly pushing into place.

For technical assistance call 1-800-CALL MTX.

These instructions are guidelines only and in no way are intended to
replace a professional installation. As always before screwing or drilling
check to make sure you will not damage any wires or hoses or cause
damage to the vehicle.

Warning: Batteries normally produce explosive gases which can cause
personal injury. Therefore, do not allow flames, sparks or lighted sub

­stances to come near the battery. When charging or working near a
battery, always shield your face and protect your eyes. Always provide
ventilation.

Conventional Wiring of Aftermarket Radio

_

+

20 Amp Fuse

Low Level Signal

Turn

On Lead

20A

PW

RGNDREM

EB

C

INPUT

RIGHTLEFT

GAI

NX-OVER

STATUS

Optional EBC

(Electronic Bass Control)

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4. Route 10ga red power wire from furnished wiring harness starting
at pre amp location. Route wire under rear seat on driver's side, over to
threshold and under carpet to the front of vehicle.

5. Open hood.

6. Drill a hole through the fire wall. Locate a spot low on the fire wall on

the driver’s side. You should always look to find a clear path. Drill a hole
from inside of the vehicle into engine compartment and insert grommet.

Firewall

Battery

Drill Hole
for Grommet

Note: To avoid any damage to parts inside engine compartment, drill
from inside of vehicle using a short bit.

7. Route 10ga red power wire through grommet into the engine compart-

ment.

8. Route 10ga red power wire through engine compartment safely away
from any moving or hot parts that could damage the wire.

9. Cut 10ga red power wire to length, connect the supplied fuse holder
from the wire kit to the end of the wire.

Optional- The EBC, or Electronic Bass Control, allows a remote bass

control to be adjusted from the driver's seat.

Setting Crossover

You should set the crossover to your own personal listening taste. The

crossover is adjustable to any frequency between 50Hz (counterclock

-

wise) to 150Hz (clockwise). As a guideline, the goal is to create the illu

­sion of bass up front. The higher the crossover point the more “audibly
visible” your sub is going to be. Take your time and really listen to your
system, grab a soda and a few of your favorite tunes and have fun.

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

18. Reinstall threshold trim. Locate and align holes in vehicle with pins on

trim; secure with the phillips head screws removed earlier.

19. Mounting of enclosure: Pass lug holding spare tire into place through
the hole in enclosure and then through a lug hole (not through the center
hole) in the spare tire. Replace washer and secure all with wing nut. Zip
cover.

Wing Nut

Lu

g

25

10. Remove 20amp fuse from MTX fuse holder. Connect furnished ring
terminal to positive side of battery. Remove 5/16" bolt from factory battery
terminal. Pass bolt through factory battery terminal, then ring terminal,
and into the other side of factory battery terminal and retighten bolt.

11. Ground amplifier to chassis of vehicle; connect the terminal provided
to the 10ga black wire from furnished wiring harness. A good ground is
as important as the power connection. The ground should be as short as
possible and the contact point should be free of paint and debris.

SPEAKER WIRES

12. In the channel on drivers' side between front and rear door locate

the rear speaker wires in the wiring harness. Colors are right channel;
blue/white (positive), blue/pink (negative), and left channel; brown/yellow
(positive), brown/light blue (negative). Tap into wires with the supplied
RCA High Level input wires and route under carpet to the rear seat, over
to pre amp on enclosure. Depending on the option package, there may be
more than one wire in these colors. The speaker wire will be the smallest
wire and twisted together.

Although, MTX has made every effort to assure proper wiring colors,
MTX is not responsible for any changes made by the vehicle manufac

­turer which sometime occur. If wiring colors do not match then physical
verification is required.

CONNECTION TO ENCLOSURE

13. Connect speaker wire RCA's to the inputs of pre-amp.

Note: Patented BTL turn on circuitry- amplifier senses DC offset provided by “high
powered” or BTL type head units. This feature turns the amplifier on automatically
if you are using high level inputs.

_

+

20 Amp Fuse

20A

PW

RGNDREM

EB

C

INPUT

RIGHTLEFT

GAI

NX-OVER

STATUS

STRIPED

SOLID

SOLID

Blue/White (+)

Blue/Pink (-)

Brown/Light Blue (-)

Brown/Yellow (+)

Optional EBC

(Electronic Bass Control)

14. Plug power harness into amplifier pre-amp.

20 A

PW

RGN DR EM

EB C

IN PU T

RI GH TLE FT

GA INX- OV ER

ST AT U

S

15. Replace 20amp fuse under hood.

16. 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.

17. Adjust gain and crossover.

Setting Gain

Turn gain knob on Thunderform pre amp to minimum, counter clockwise.
Play a favorite tape or compact disc 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 clock

­wise until the speaker starts to distort and reduce gain to loudest listening
level before distortion.

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