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TSB 08-024-05

Radio Communication Equipment Installation Recommendations

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Date: 08-024-05  

Models: 2001-2006 (BR/BE/DR/DH) Ram Truck

2001 - 2003 (AB) Ram Van/Wagon
2001 - 2004 (AN) Dakota
2001 - 2002 (BR/BE) Ram Pick Up
2004 - 2006 (CS) Pacifica
2005 - 2006 (DH) Ram Pick Up - Heavy Duty
2001 - 2003 (DN) Durango
2002 - 2006 (DR) Ram Pick Up
2004 - 2006 (HB) Durango
2001 - 2006 (JR) Stratus/Sebring
2002 - 2006 (KJ) Liberty/Cherokee
2006             (LE) Chrysler 300 (International Markets)
2001 - 2004 (LH) Intrepid/Concorde/300M
2005 - 2006 (LX) 300/Magnum/Charger
2005 - 2006 (ND) Dakota
2001 - 2005 (PL) Neon
2001 - 2002 (PR) Prowler
2002             (PG) PT Cruiser (International Markets)
2001 - 2006 (PT) PT Cruiser
2001             (R1) Dakota (International Markets)
2001 - 2006 (RS/RG) Town & Country/Caravan/Voyager
2001 - 2002 (SR) Viper RT/10 & GTS Coupe
2001 - 2005 (ST) Stratus Coupe/Sebring Coupe
2001 - 2006 (TJ) Wrangler
2004 - 2006 (VA) Sprinter
2001 - 2004 (WJ/WG) Grand Cherokee
2005 - 2006 (WK/WH) Grand Cherokee
2006             (XK/XH) Commander
2001             (XJ) Cherokee
2003 - 2006 (ZB) Viper
2004 - 2006 (ZH) Crossfire Coupe/Crossfire Roadster

The information contained in this guide has been prepared for use by persons installing
accordance with current engineering principles and generally accepted practices, using the
best information available at the time of publication. It is not possible to cover all of the
possible installations of two-way radio equipment in this guide. Accordingly, DaimlerChrysler
Corporation cannot be held responsible for incidental or consequent damages arising out of
the use of the information contained herein. Installations and modifications are solely the
customer’s responsibility.

The installation recommendations presented here are intended to supplement the radio
manufacturer’s instructions. To assist in properly installing communications equipment in
DaimlerChrysler vehicles, the following information is provided. Always use good installation
practices (see The American Radio Relay League (ARRL) Handbook or other standard

Test the entire installation for anomalies, especially drivetrain and brake control before
extensive driving. If any problems occur the owner’s first line of contact is the vehicle dealer.
The literature supplied with each vehicle lists the steps to be taken in the event the dealer is
unable to resolve the problem.

Mount the transceiver to a solid surface. If you use screws through the floor, put body sealer
over the underbody projections. Stamped acorn nuts, filled with sealer are available at most
body shops for this purpose. This will keep moisture out of the carpet and insulation, and will
forestall rust in this area. Watch out for wire harnesses routed under carpet and behind the
instrument panel. Do not drill holes. Instead, use an awl to pierce the hole. Not only is damage
less likely, but the extruded sheet metal will resist strip out much better.

If you mount the radio under the instrument panel, be sure that there is no interference with
proper operation of the foot controls. Mount the control head or front panel (especially the
microphone cable) so that it is clear of the steering wheel and steering column controls and
passenger airbag. If the unit is heavy, extra bracing may be needed for stability. Newer
vehicles have more structure and energy absorbing materials in the knee blocker (the lower
part of the Instrument Panel). A communications speaker (with or without DSP), directed
toward the operator, will enhance intelligibility under mobile conditions.

Many factory entertainment radios have a “mute audio” input that may be used with the
Push-To-Talk (PTT) line to mute the audio system during transmit. This information is usually
in the service manual.

Try the installation out before you start drilling holes (Velcro or other hook-and-loop is useful).

To reduce the hazard of working on the vehicle, disconnect the NEGATIVE battery cable before
beginning work.

NOTE: Some components may lose short-term memory (e.g.: engine or transmission
adaptive parameters, radio presets etc.) after an extended length of time
without battery power.

For low or medium power transmitters (up to 55W FM or 110W SSB or CW), the interior
power distribution center or the power outlet or cigar lighter feed may be used. Use an
appropriate jumper terminal at the socket or splice (solder and heat shrink or tape). For higher
power transmitters, including amplifiers, connect the power (battery positive) lead at the
battery or at the power distribution center or at the positive jump-start post, if equipped. If
ignition switching is desired, use a relay to prevent overloading the ignition switch. Appropriate
terminals should be used. If a terminal is exposed to the weather, solder and apply a
commercial protectant (wheel bearing grease is an acceptable alternative) to retard corrosion.
The power lead should be fused as close to the battery as practical to protect the wiring and
the vehicle! If the power connection is underhood, use a weatherproof fuse holder. These are
usually available from a trailer supply or marine dealer.

Vinyl-insulated wire, typically supplied with transceivers is not entirely suitable for the higher
underhood temperatures in modern vehicles. Route the underhood wiring away from all hot
areas, away from the exhaust, radiator, A/C liquid line and engine. Along body sheet metal is
usually the coolest location.

DO NOT FUSE THE GROUND LEAD! If the ground-side fuse were to open, the entire supply
current would be conducted by an alternate current return path, which may cause the feed line
to overheat, with possible resulting damage.

For low or medium power installations, connect the ground (battery negative) to body sheet
metal near the power feed point. If you use a screw through the floor, use body sealer over
the underbody projection. For high power installations, connect the ground (battery negative)
lead at the battery connection to the body. This is usually a 6 or 8 AWG black wire from the
battery negative terminal to a screw at the wheelhouse or radiator support. If a separate sheet
metal ground is used, clean the paint off a one inch or so diameter area of body panel where
the ground lead is to be connected. An awl is the best tool to use to pierce a starting hole for a
#12 or 5mm, minimum, plated ground screw. A flat ring terminal of the proper size for the
screw with separate serrated washer (not a split or SAE) lock washer should be used between
the terminal and the screw head, not between the terminal and the surface. As above, some
grease or protectant should be used if the connection is in an unprotected area.

It may be possible to route power wires through the hood gutter into the door gap, into the
passenger compartment. If the power cable must pass through the dash panel, try to find an
existing hole with a grommet that is unused. If none is available, pull the carpet back from
under the dash panel in the passenger footwell in the cabin. Locate a place where there are
no other components on either side, as high up as possible. An awl is the best tool to use to
punch a small hole through to the engine compartment. If the position is good, enlarge the
hole by driving the awl in up to the shank. If this is not large enough to easily pass the cable,
enlarge it by using a larger tapered punch. This will leave an extruded hole with no sharp
edges. Install the cable and seal the hole with silicone RTV or commercial body sealer on
both sides. Seal any extra holes that you may have made. Dress the underhood wiring so that
it is safe from all hazards, which include the following: exhaust manifold, steering shaft,
throttle linkage, fans, etc. Provide a outside drip loop where wires pass through the
compartment panels and tie wrap or tape as required keeping the wires where you put them.

Route control cables under the floor mats, inside the corner where the floor pan meets the
rocker panel for best protection. Remove the sill plates and tuck the cable under the floor mats
or carpet and padding. For most left hand drive vehicles, use the right side for best separation
to the main body harness which is usually on the left side.

Route the cable along the extreme outboard edge of the floor pan, under the side trim, if

For trunk mount installations in passenger cars, you may need to remove the rear seat cushion
and seat back to get the cable into the trunk. The seat cushion is usually clipped at the front,
lower edge by its own frame: push down and back, then lift. Note the front and rear clipping
points for ease of reinstallation. The seat back is usually clipped to the rear compartment inner
panel: pull out at the bottom and slide up to remove. Again, note the clipping points for ease of
reinstallation. There is usually a vapor/sound barrier behind the seat back, which must be
pierced to pass the cable through.

Open the trunk and pick a spot where the cable is safe from chafing on any sharp sheet
metal. Tie wrap or tape in place at this location. Repair the barrier sheet if necessary. Replace
the seat back and cushion, taking care that the cable is not pinched by the seat cushion when
there is someone sitting in the seat. On some vehicles, there may be a channel for wiring at
this location. Newer vehicles have seatbacks that fold down, which may provide a very simple
pass through method. Watch for and avoid pinch points!

For remote control radios, a sheet of 1/29 plywood one or two inches larger than the radio, is a
good method to mount the transceiver to the shelf. It provides a good mounting surface, some
shock and vibration isolation, and it keeps moisture away from the radio. Mounting on the floor
of the trunk is not recommended. To conserve trunk space, in some vehicles, the radio may
be mounted to the rear compartment panel. Locate as far as possible from any vehicle
electronic modules located in the rear of the vehicle.

In any case, provide good air circulation; a 50 watt RF output FM transmitter will dissipate
about 22 watts (@70% efficiency). Do not obstruct the cooling air flow.

The transmission line (coaxial cable) should be treated in the same way as the control and
power cables. Route flat along body sheet metal wherever possible to avoid sharp edges and
pinches. If it is necessary to cross over wiring, cross at right angles. In some cases, additional
grounded shielding between the transmission line and the vehicle wiring may be helpful. It is
important to maintain the maximum spacing from the vehicle harnesses, especially if the
antenna is not a good match. Use the best cable available (98-99% braid coverage or braid/foil)
especially at VHF and above. Mechanical pressure on the cable can cause degradation or
even short circuits. Do not rely on the obsolete military ’RG’ designations as an indicator of

Cut off excess transmission line, coiling forms a choke balun, and terminate in the correct

The use of N, BNC or C connectors are recommended over 9UHF9 (PL-259/SO-239)
connectors. A small amount of silicone dielectric grease (not the white heat sink compound) in
the connector (after soldering) will minimize condensation problems. Cut the line as short as
practical, to minimize losses.

Antenna location is the most important consideration in any mobile installation. For VHF and
UHF antennas the recommended place on almost all vehicles is in the center of the roof.
Antenna mounting location must not cause radiation into the passenger compartment.

NOTE: There may be GPS, cellular, satellite radio or newer technology antennas
located in or on the vehicle. They may contain sensitive low noise amplifiers
(LNAs), operating at 0.9, 1.575 and/or 2.3GHz. If you are unsure of interactions,
test with a temporary installation (a magnetic mount will do) before committing
to a permanent hole.

Deck lid installation is not recommended. Glass-mounted antennas should be mounted at the
very top edge of the clear portion of the glass away from the heater grid. Vehicles with
printed-on-glass (active) antennas may be damaged by through-glass installations.

NOTE: Composite panels, such as roof or deck lid may contain hidden receiving or
transmitting antennas.

For HF antennas, refer to the manufacturer’s instructions and follow them closely, unless you
are an accomplished antenna experimenter. HF antennas should be mounted to the body or
frame steel for a good counterpoise as well as structural strength. 29 x 39 aluminum
architectural tubing (or 29 x 49 U-channel for heavy HF antennas) may be cut and welded into
many simple structures to mount HF antennas, and it is easily modeled by using 2x4s.
Aluminum bumpers are heavily anodized for corrosion protection and the coating (aluminum
oxide) is very hard as well as non-conductive. A small grinder with a coarse stone will break
through the anodized coating for electrical connection.

Remember for all monopole antennas, the vehicle is the other half of the radiator. At HF the
vehicle may be shorter than a quarter wavelength, resulting in some significant unbalanced
currents flowing on the body.

Permanently installed antennas are preferable over magnetic, glass or body-lip mounts for
anything other than for low power or temporary installations. Most of these alternate antennas
will reflect some power back at the feed point. Much of this will be radiated from the feed line
inside the passenger compartment, and may be picked up by the vehicle wiring.

For deck lid installations for HF or low VHF (6m), the deck lid should be bonded to the body
across the hinges with short, wide tinned braid straps or thin brass strip. They must connect to
clean sheet metal at both ends. For AM/SSB and even some FM installations, the hood
should be bonded to the body. In some cases, the doors may need to be bonded as well.

Glass-mount antennas may not work or will only work very poorly in vehicles with metallized
glass (Electrically-heated windshields or some solar reflective glass). Non-metallic bodies
(e.g., Viper) require a half-wavelength antenna or a ground plane with radius equal to a
quarter-wavelength for a quarter-wave antenna. Copper or brass are the best choices, but
aluminum or even steel may be used. Install on the inside of the body panel with a good
adhesive or tape and provide a good RF connection to the coax shield at the feed point.
Screen, mesh or thin sheet stock, even copper or aluminum tape may be used. Shape is not
critical, but some directional characteristics may be noted if it is not round. Try to stay
one-quarter wavelength away from edges, including sunroof openings.

For VHF and UHF, a good quality 9NMO9 (New MOtorola) base or other mount with feed line
(center conductor and shield) soldered to base is recommended. This will allow the maximum
flexibility in antenna selection and is the best choice for electrical and mechanical
considerations. Use the proper hole saw 3/49 for NMO, Motorola P/N 0180356B77) or have it
done professionally if you are not comfortable with power tools. Consider roof reinforcements
and the sunroof mechanism for interference to the base and to the feed line. The dome lamp
opening often provides convenient access at or near the center of the roof. Hole plugs are
available, for use at sale or trade-in, if you expect to remove the antenna base.

To install the antenna base in the hole, remove the one or two-door trim pieces at the pillar
where the cable is to be routed and ease the headliner away from the roof. Insert a piece of
flat steel or plastic banding ½9 to ¾9 wide) and guide to the desired corner. Pull the banding
through, leaving 69 which can be taped to the transmission line (easier without the connector,
but possible even with a PL-259). Continue pulling until the antenna base is one inch or less
from the hole, then seat the base and screw on the outside ring, O-ring down. A little silicone
grease helps maintain a good seal for the life of the vehicle. Tighten with an open-end wrench,
and apply a small amount of silicone grease to the contact and insulator surface of the base.
This will help exclude water, but must be renewed periodically. Tip: if you remove your
antenna to go through the car wash, there are caps available to exclude water during the

In most vehicles, RG-58 sized cable will fit between the pillar trim and body sheet metal. If
necessary, the technique used on the roof can also be used to snake the cable down the
inside the pillar.

All radio installations must follow the personal exposure recommendations in FCC
Bulletin 65.

Install the connector very carefully. There are good instructions in The ARRL Handbook. Use a
clean, hot, high-wattage iron and work quickly, to prevent damage to the cable dielectric. If
you are a beginner or are not comfortable with this kind of detail work, ask for help. It is
extremely important.

Policy:    Information Only

I would like to thank Bob Bergevin, Arthur Cantrall, Barry Drodge, David Lovell, Bill Maurits, and Steve for supplying the information for these bulletins. And a big thank you goes to Geno's Garage for making possible.


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This page was edited on: May 3, 2004