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Author Topic: Toyota 4Runner installation  (Read 2172 times)
K3IMW
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Posts: 80




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« on: August 19, 2004, 12:39:09 PM »

A friend has purchased a new 4Runner. The handbook has a warning in several places about installing 2-way radios.

I assume there's a problem with possible interference with onboard electronics, and Toyota is being ultra-careful. Anyone know of Toyota guidelines for an acceptable installation?

73 de ian, k3imw/6
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K0BG
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« Reply #1 on: August 19, 2004, 05:02:10 PM »

Almost without exception, there are disclaimers in every current vehicle manual. This is more an issue of litgation than basis of fact. If you follow the correct procedures in properly installing radio equipment and their requisite antennas, you won't have a problem.

If you are not familiar with the correct procedures, visit my web site as a place to start.

Alan, KØBG
www.k0bg.com
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K3IMW
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« Reply #2 on: August 19, 2004, 05:54:22 PM »

Thanks, Alan, very informative stuff there. Have forwarded the URL to my friend.

73 de ian, K3IMW/6
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KB1LKR
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Posts: 1898




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« Reply #3 on: August 19, 2004, 06:20:33 PM »

In any case, use fused, *twisted* pair (to the extent heavy gauge pair can be twisted) from battery as direct as practical and stay away from on board computer and air bag controllers. Believe GM, for example, recommends running from right hand side battery across at radiator top (vs along rear engine  firewall) rearward at left fender inside thru firewall for their SUV's. Avoid mechanical and thermal hazards. Do not parallel vehicle wireing harnesses for long distances, etc. Per Ford, ditto for antenna coax, and high quality, high shield coverage (>95%) cable and minimum antenna SWR/mismatch.

Google for: "Ford Mobile Radio Installation Guidelines 04 march 1998" also similar from GM and Chrysler and others, try starting at GM's fleet/police specialty vehicles page for the Blazers and Caprices for the GM data. None is specific to Toyota but all give practical guidelines for modern auto installations.
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KB1LKR
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Posts: 1898




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« Reply #4 on: August 19, 2004, 07:55:02 PM »

Search for:
GMNA Engineering Centers
Radio Telephone / Mobile Radip Installation Guidelines January 2002

<quote>

5. Radio Wiring and Connection Locations
A. Connecting radio power on General Motors vehicles is model dependent. The installer must decide which one of the following four methods will be appropriate.
1.) Connect the positive and negative leads directly to the battery terminals (illustrated in this guideline).
2.) Connect the positive lead to the auxiliary power terminal (located at the underhood fuse center or identified by a red plastic cover in the underhood area) and connect the negative lead directly to the negative battery terminal.
 3.) Connect the positive lead to the auxiliary power terminal and connect the negative lead to the battery body connection point (identified by a short #10 AWG or larger wire running from the negative battery terminal to the body of the vehicle).
4.) Connect the positive and negative leads to the Special Equipment Option (SEO) wiring provided for this purpose.
B. If connections are made directly to the battery terminals, the GM approved methods of connecting auxiliary wiring include the adapter package illustrated in Figure 2, NAPA-Belden replacement battery bolts (part # 728198), or drilling and tapping the hex end of the original battery bolts 10-32 X 3/8" deep.
NOTE: It is recommended that a fuse be placed in the transceiver negative lead to prevent possible transceiver damage in the event the battery to engine-block ground lead is inadvertently disconnected.

<snip>

6. Radio Wire Routing
A. The power leads should be brought through a grommeted hole in the front bulkhead that must be provided by the installer. For trunk-mounted transceivers, the cables should continue on along the driver's side door sills, under the rear seat, and into the trunk through the rear bulkhead. All attempts should be made to maintain as great a distance as possible between radio power leads and vehicle electronic modules and wiring.

B. If the battery is located on the passenger side, radio power leads should cross the vehicle in front of the engine.

<end quote>

Also search for:
Chrysler Corporation
Radio Communication Equipment Installation Recommendations

<quote>
The **positive** power connection should be made directly to the battery and fused as close to the battery as possible. **The negative power connection should be made to body sheet metal adjacent to the negative battery connection. This connection should not be fused.**

Antennas for two-way radios should be mounted on the roof or the rear area of the vehicle.Care should be used in mounting antennas with magnet bases. Magnets may affect the accuracy or operation of the compass on vehicles so equipped.

The antenna cable should be as short as practical and routed away from the vehicle wiring when possible. Use only fully shielded coaxial cable.

Carefully match the antenna and cable to the radio to ensure a low Standing Wave Ratio(SWR).

<snip>

2. **POWER** WIRING Connect the power (battery +) lead at the battery or at the power distribution center **or at the positive jump-start post**, if the vehicle has one. A ring terminal of the proper size should be used; solder if the terminal is exposed to the weather. Wheel bearing grease or a commercial protectant should be used to slow corrosion. This lead should be fused as close to the battery as practical to protect the wiring (and the vehicle)! If the power connection is under hood use a
weatherproof fuse holder. Motorola Communications Division supplies a weatherproof holder, part number 09-84277B01 for 5AG cartridge fuses that is part of their standard installation kit. Packard Electric Division of GM makes an insulator, part number 12033769, terminal number 12020156 with cover 12033731 for standard SAE plastic fuses.



Vinyl-insulated wire, typically supplied with transceivers is not entirely suitable for the higher under hood temperatures in modern vehicles. Route under hood wiring away from all hot areas. Body sheet metal, away from the exhaust, radiator, A/C liquid line and engine 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 the coax shield. This could cause the feedline to overheat, with possible resulting damage.

Connect the ground (battery -) 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 (usually the case with commercial trunk mount radios). An awl may be used to pierce a starting hole for a #12, minimum, plated ground screw. A ring terminal with lock washer serrations of the proper size for the screw or a separate serrated (not a split or SAE) lock washer should be used between the terminal and the screw head. As above, some grease or protectant should be used if the connection is in an unprotected area.

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 foot well in the cabin. Locate a place where there are no other components on either side, as high up as possible. An awl may be used 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. Tie wrap as required.


3. CABLING 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 (usually on the left side).

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

<snip>

5. TRANSMISSION LINE 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 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 UHF 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 quality.
The use of N. BNC or C connectors is recommended over "UHF" **(PL-259/SO-238)**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.

6. ANTENNA LOCATION 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. The center of the **deck lid** is an acceptable alternate. 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 antennas may be damaged by through-glass installations.**


<end quote>

Note the differances of opinion on fusing the negative/ground lead. Ford just recommends "a [one?] weatherproof fuse holder..." and defines low SWR as "reflected less than 10% (VSWR < 2:1)" and advises additional cautions for high power (>100W) insrtallations.

Anyway it's general information to guide you. Perhap the Toyota dealer has a service bulletin etc. with more specific factory info.


 
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K0BG
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« Reply #5 on: August 20, 2004, 10:10:41 AM »

Twisting power cabling will do absolutely nothing for noise abatement. All it will do is make installation difficult and potentially dangerous!

GM's info and that of other makers are inline with standard installation practices. However, some of the RPOs (Regular Production Option) referred to in the aforementioned are not available on non-police vehicles.

Secondly, attaching any amateur radio to any specified location which is not adequate to supply the necessary power requirements is a disaster in the making. Ford's and Dodge's police vehicles do supply 50 amp switched and unswitched circuits. Those on GM products are only 40 amps and in two cases 20 amps. While these special RPOs will certainly supply adequate power, they are paralleled with the rest of the vehicles wiring which allows both egress and ingress of RFI, EMI, and induced noise. Personally, I'd avoid them.

Alan, KØBG
www.k0bg.com
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KB1LKR
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Posts: 1898




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« Reply #6 on: August 24, 2004, 01:21:39 PM »

Good point, some of the material in the service bulletins assumes police or utility power wiring options, but it you follow the instructions for direct to battery and disregard the parts about aux power wires it is still useful.

Interesting to note is differances in recommendations for fusing ground in addition to the +12V leads from battery. Interesting.

Re: Twisted pairs, twisting should reduce RF  radiation from and susceptability to radiated RF, however it will do nothing to stop conducted RF noise from other sources, nor from the radio (if any), so in reality it will not do very much for noise immunity I'm not sure I see any potential danger in twisted pairs vs untwisted, just inconvenience, particularly for large gauges, though I (and the service bulletins that recommend it) could easily be overlooking something.
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