This document contains some guidelines for the D.C. power wiring of Syntor, Syntor X, Syntor X 9000, Syntor X 9000E and Spectra radios. These are only general guidelines. They may not work and may not be safe if you simply attempt to blindly follow them like a set of instructions. They need to be interpreted and applied by someone with prior knowledge/understanding about wiring high power mobile radios. The primary reason for this page is things have changed since the original Motorola installation manuals were written (knowing what is in these manuals is still extremely important). Even if you think you know what you are doing, the Motorola manuals and safety advisories should still have been read first. The secondary reason is just for cataloging "distilled" background information specifically about these radios.
It is assumed you want to install your mobile radio in a vehicle with a negative ground chassis (i.e. the negative terminal of the vehicle battery is connected to the chassis). If you have a positive ground vehicle DO NOT use these guidelines. In this case get a service manual for the radio and figure out how to do the correct positive ground installation. Some of these radios will NOT install in a positive ground vehicle. The Spectra will not and I have seen Syntor X 9000 radios that have a sticker inside that states the radio drawer is not for positive ground installations. One problem is some Syntor X 9000 radios have the common circuits board ground wired to the chassis, which prevents positive ground use and can damage the radio if you hook one of these up in a positive ground vehicle. Even fused power wires can still cause damage to the radio in a case like this. The question your radio will answer for you is, will the fuse or the copper traces on a circuit board blow up first?
As I have already mentioned in the web site introduction, I do not have comprehensive safety warnings on this web site. I will however mention that whenever working with or around automotive batteries, always at least wear eye protection. Automotive type batteries can possibly explode. I know of a former tow truck driver that almost completely lost his eyesight when a battery he was jumping unexpectedly exploded. Debris and liquid sulfuric acid hit his unprotected eyes, caused eyesight loss (permanently blinded in one eye and just damaged in the other eye) and could have completely blinded him. Always treat these with the respect they deserve.
Every radio wire connected to the vehicle power must be fused. The fuse will do its best to protect the radio and the wire between the fuse and radio. Fuses should be mounted as close as practical to the power source they attach to (i.e. vehicle battery, existing vehicle wiring, etc.), even if you have to use a second fuse at the power source. This prevents a shorted wire in a long wire run from directly shorting out the power source. Unprotected vehicle battery positive wires can become vehicle metal welders/cutters until the shorted wire vaporizes or melts and breaks (sometimes the wire insulation melts and the damage from an unfused wire can follow the wire across the vehicle). These types of unfused short circuits can also start fires.
Any and all the power fuses are fast blow types. Do not use slow blow or delayed response fuses.
Protect all wires including the power wires from sharp edges and being pinched or crushed.
If you reverse the positive and negative power to the radio, even for an instant, even with a fused power wire, you can seriously damage the radio. The damage can range from fatal (i.e. throw the radio away) to reasonably repairable. If you are not clearly sure about what you are doing, then don't do it!
Since ring terminals and fuse holders are typically installed near or at the vehicle battery, they are subject to degradation from exposure to the battery fumes. Wire crimps are especially susceptible. From time to time, crimps will go bad and not be able to reliably pass large amounts of current, if any at all. Voltmeters will not identify this condition unless a large amount of current is being drawn through the crimp while the voltage, opposite the battery side of the crimp, is being measured. These types of connections must be physically inspected. This is always an ongoing maintenance issue. On a similar note, all the other power connections, no matter where they are located, need to be checked periodically for corrosion and to make sure they are still tight. An ohmmeter will not identify a bad ground connection, unless it has totally failed. These must also be physically inspected.
Always make sure the fuse rating matches the gage of the wire it is attached to. A 30 or 40 amp fuse on a 12 gage wire is a recipe for disaster. A 30 or 40 amp fuse should only be installed on an 8 gage or heavier wire (use the original Motorola factory fuse rating). Higher current fuse ratings or very long power cable runs require even heavier gage wires. This is one of the cases where you should absolutely know what you are doing or absolutely use only the correct original manufactures wiring, accessories and installation instructions.
When wiring the radio, first take the large gage black wire and connect it to the vehicle chassis. Pick some place close to the radio drawer where there is sheet metal that you can put a screw into (do not damage anything below the sheet metal with the screw tip or when drilling a pilot hole) or where there is already an existing screw or bolt you can use. Make sure the large black ground wire has good electrical contact with the metal surface. Do not run the large black wire to the vehicle battery - connection. If the existing vehicle wiring develops a bad connection on its ground cable (between the battery and chassis), and you have the radio large black wire connected directly to the battery negative terminal, the failed vehicle wiring will then use your radio wiring as a ground for all the vehicle battery loads (including high current starting). These high current loads can do really, really bad things to your radio in a heart beat. Radios that are designed to hook directly to the battery negative terminal have a fuse in the black ground wire. The ground wires for these Motorola radios are designed to hook to the chassis, not the battery.
Second, take the large gage red wire and route it up to the vehicle battery. Then install a large fuse holder (sometimes missing from used equipment) with at least a 30 amp fuse for high power radios or 15 amps for medium/low power radios. One side of the fuse holder connects to the vehicle battery positive terminal, with as short a wire as practical between the battery and fuse holder (this fuse can not protect the wire between it and the battery from shorts). The other side of the fuse holder attaches to the large red wire from the radio. Do not put the fuse in the holder until you are done with the rest of the install. Do not connect this red wire to any existing vehicle wiring (like a lighter socket). These radio power wires usually can draw lots more current than any existing vehicle wiring can support and the existing vehicle wiring usually has lots of electrical noise from being run all over the vehicle in large bundles of wires. The battery positive terminal is the only place for this large gage red wire.
Speaking of existing vehicle wiring and power connections - BEWARE, some newer vehicles have internal power supplies of 40+ volts or higher. That innocent looking vehicle power wire under the dash or on a vehicle fuse block might be waiting to kill your radio dead on contact! Even worse, hooking a 12 volt radio up to it might also damage the vehicle while the radio is in it death throws. Nowadays, always use a volt meter first (both with the vehicle running and not running) to check the voltage of any existing vehicle wiring before hooking anything to it.
The reason for the higher voltages is it solves a new problem. With newer vehicles having so much "body" electronics built in, there are now larger wiring harnesses and lots more of them just to connect all the body electronics. The simple power formula of (Power = Voltage times Current) tells us that higher voltage systems have lower current in their wiring for the same amount of power carried. Lower current means the wire gage number can be increased (i.e. decreased wire diameter). This makes the vehicle wiring harnesses smaller. All the new body electronics can be a big problem for two-way communications radios, so you should route ALL your radio wiring as far away as possible from any vehicle body electronics or their wiring. This can also affect where you mount the radio, control head and antenna. Since many of these new body electronics systems are actually networked microprocessors, they can be noisy. This is why you even want to keep the radio power leads as far away as possible from existing vehicle body wiring. Occasionally, the vehicle manufacturer or dealer might be able to offer help for a correct mobile radio install. Usually they just announce their warranty disclaimer and say you should not install high power communications radios in the vehicle. Well that is unless you are a large contract consumer, like a police department, then they show a more reasonable attitude. There are some Internet resources dealing with these problems that you can search for.
If you have a vehicle with multiple batteries (like a diesel), find out how to correctly connect 12 volt accessories to the correct battery first.
These used both clamshell, Sys 90 and Sys 90*s control heads. They are supposed to follow the same green radio power and orange ignition sense wiring scheme used by the other radios (Syntor X 9000, Spectra, etc.). However, unlike other radios the connectors have removable pins for the green and orange wires. So, with used radios there is no guarantee that the green/orange color code will be correct. If you are not sure if the power wires are the correct ones located on the correct connector pins, refer to the Motorola manual before connecting the wires. Remember, even with a 3 or 4 amp fuse on the power wires the radio can still be damaged if the connections are not correct.
At the control head side of the connector there is a green and orange wire (see above paragraph about possible problems with the wire color or which connector pin its located on). The green wire goes through a 3 or 4 amp fuse to the battery + voltage. This does not have to be the actual battery positive terminal. However, wiring it to the battery positive terminal is better for preventing unwanted noise pickup from the existing vehicle wiring. If you do not wire to the vehicle battery, you may need a noise filter in-line with this wire. The orange wire can be connected to the green wire if you do not want to use the ignition sense feature. If you want to use the ignition sense feature, then the fused orange wire should be connected to a power source in the vehicle that is only on when the vehicle ignition switch is on.
Another difference is the ignition sense wire actually carries power for the microphone PTT switch and to the radio drawer. So, noisy power sources must be filtered with an in-line noise filter or fed through a relay contact (the relay coil is controlled by the vehicle ignition switch) from a clean power source like the battery + terminal.
The original Syntor radio drawer cable connector was used on other older models of Motorola radios. Some of these radios used to have different gauge wires (as in smaller wire sizes) for the main red and black power wires. Always make sure the gage of these wires is correct for high power radio drawers.
At the control head side of the connector there is a green and orange wire. The green wire goes through a 3 or 4 amp fuse to the battery plus voltage. This does not have to be the actual battery positive terminal. However, wiring it to the battery positive terminal is better for preventing unwanted noise pickup from the existing vehicle wiring. If you do not wire to the vehicle battery, you may need a noise filter in-line with this wire.
The orange wire is an ignition sense wire. The Radio Service Software can program the radio to use the ignition sense or to ignore it. This will make the radio do different things depending on the vehicle's ignition key being on or off. If you do not care about using this feature, just connect the orange wire to the green wire. If you want to use the ignition sense feature, then connect the orange wire to its own 3 or 4 amp fuse and then to the vehicle's wiring. Choose a vehicle wire that only has positive voltage on it when the vehicle ignition is turned on.
As long as the ignition sense wire is not used to power anything (i.e. just as a sense lead), it usually does not need any noise filtering like the green wire does.
Some of the newer Syntor X 9000, Syntor X 9000E and Spectra control heads have optional internal jumpering to bypass the control head power switch (where the green wire connects) and power the control head from the orange ignition sense wire (allowing the vehicle ignition switch to turn the radio on and off). If your control head is setup to use this feature, you have two choices to solve this clean power source problem. First is an in-line noise filter. Second is a relay that is energized/controlled by the vehicle's ignition switch and the isolated relay contacts switch the fused positive battery connection to the orange ignition sense wire.
The original cable remote mount gets its control head power from the large gage power wires in the back of the radio drawer or through the remote mount cable. The only additional power wiring is the ignition sense wire on the DB-15 connector that plugs into the "pig tail" cable from the control head.
As long as the ignition sense wire is not used to power anything (i.e. just as a sense lead), it does not need any noise filtering. However, some Spectra radios have been modified to power the control head from the ignition sense wire. In this case, you have two choices to solve this clean power source problem. First is an in-line noise filter. Second is a relay that is energized/controlled by the vehicle's ignition switch and the isolated relay contacts switch the fused positive battery connection to the ignition sense wire.
The motorcycle remote mount gets its control head power from the large gage power wires in the back of the radio drawer through the remote mount cable. The only additional power wiring is the ignition sense wire on the DB-15 connector that plugs into the back of the radio drawer.
As long as the ignition sense wire is not used to power anything (i.e. just as a sense lead), it does not need any noise filtering. However, some Spectra radios have been modified to power the control head from the ignition sense wire. In this case, you have two choices to solve this clean power source problem. First is an in-line noise filter. Second is a relay that is energized/controlled by the vehicle's ignition switch and the isolated relay contacts switch the fused positive battery connection to the ignition sense wire.
The dash mount gets its control head power from the large gage power wires in the back of the radio drawer. The only additional power wiring is the ignition sense wire on the DB-15 connector that plugs into the back of the radio drawer.
As long as the ignition sense wire is not used to power anything (i.e. just as a sense lead), it does not need any noise filtering. However, some Spectra radios have been modified to power the control head from the ignition sense wire. In this case, you have two choices to solve this clean power source problem. First is an in-line noise filter. Second is a relay that is energized/controlled by the vehicle's ignition switch and the isolated relay contacts switch the fused positive battery connection to the ignition sense wire.
The high power vehicle based stereo market has produced some new products for high power (i.e. high current wiring) vehicle sound systems. If you have more than one two way radio in your vehicle or you swap radios out from time to time, this type of wiring can be a joy to use.
Prices range from high for brand name to reasonable for no name parts. They are usually brass or gold plated, very heavy duty power wiring parts. You can get everything from heavy duty firewall grommets, fuse blocks, etc., to very heavy gage main power wires. Personally, I use a 4 gage wire from the vehicle battery to a high current sealed fuse holder, then rout it through the frame and into a fuse block at the radio. The radio fuse block takes a 4 gage wire in (it has expansion 4 gage connections to daisy chain extra fuse blocks) and has four separate fused outputs that each take up to an 8 gage wire. The ground uses an unfused solid block that takes a 4 gage wire in (it also has 4 gage expansion connections) and has four separate outputs that each take up to an 8 gage wire. I also used two 4 gage wire terminal lugs (one at the battery positive terminal and one for the vehicle chassis ground). All these parts use set screws instead of crimps to attach the wires. Wiring maintenance as well as changing out radios and cables is no longer the chore it used to be.
The 8 gage Syntor X 9000 and high power Spectra wires are perfect for these fuse block connections. I also attach the small gage remote mount control head fused wires to the fuse block 8 gage connections. Because my vehicle requires the ignition key to be on to power the accessory plugs, I wired in a fused accessory plug to the fuse block to bypass that problem. I also have this type of stuff on my test bench, but only with 8 gage wiring.
Check out the web for these parts. The PartsExpress web site
has examples of both high price and reasonably priced parts. It
is not always easy to get their search engine pointed at the right
stuff, but once you do it has additional links to all the similar
stuff. I was also surprised to find a local high end car stereo
shop had nice 4 gage terminal lugs for only a few dollars more
than the no name mail order parts.
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PL, Private Line, DPL, Digital Private Line, Vibrasponder, MPL, Talkaround, MDC-600, MDC-1200, MVS-20, Securenet, Smartnet, Privacy Plus, Trunked X2, Trunked X3, Touch Code, Quick Call II, Channel Scan, Talkback Scan, System 90, System 90*s, Systems 9000, PAC, PAC-PL, PAC-RT, PAC-TR, PAC-TL, MX-310, HT220, Mitrek, Micor, Spectra, MataTrac, Syntor, Syntor X, Syntor X 9000 and Syntor X 9000E are trademarks of Motorola Inc.