Re: Definitely OT VHF Radio Install..Ford F250
Posted: Tue Sep 02, 2014 8:36 pm
Correct. It's the current draw (amps) that is the concern.
I have seen newer lighters at around 10 to 15 amps current draw. It varies depending on the vehicle manufacturer. Some are still 20 amp, but not all.
The Motorola 55watt and 65watt two way radios that I used to install needed a absolute minimum 20 amp fuse to operate. The current draw hits the maximum when transmitting. A long conversation will burn out a small amp fuse every time.
The wiring harness that came with the radios had 10 gauge, high strand count wire for the positive and negative connections.
In vehicle wiring, the gauge is the same as building wiring.
15 amps--14 gauge
20 amps--12 gauge
30 amps--10 gauge
That allows for 10 feet run of wire from the battery to the load(in this case a radio)
It's always a longer distance than you think.
You CAN get by with smaller gauge wire but you will get a voltage drop which decreases the radio performance greatly.
In the newer vehicles the manufacturers calculate wire sizes and distances so they can use the smallest possible wire. I have seen 16 gauge wire on a 20 amp circuit. They calculate that it is a 2 foot cable run and powers something that is not affected by a voltage drop. Or a lighter that is only operated for a short period of time. Constant duty items like the heater motor still get 10 gauge wire.
I have seen newer lighters at around 10 to 15 amps current draw. It varies depending on the vehicle manufacturer. Some are still 20 amp, but not all.
The Motorola 55watt and 65watt two way radios that I used to install needed a absolute minimum 20 amp fuse to operate. The current draw hits the maximum when transmitting. A long conversation will burn out a small amp fuse every time.
The wiring harness that came with the radios had 10 gauge, high strand count wire for the positive and negative connections.
In vehicle wiring, the gauge is the same as building wiring.
15 amps--14 gauge
20 amps--12 gauge
30 amps--10 gauge
That allows for 10 feet run of wire from the battery to the load(in this case a radio)
It's always a longer distance than you think.
You CAN get by with smaller gauge wire but you will get a voltage drop which decreases the radio performance greatly.
In the newer vehicles the manufacturers calculate wire sizes and distances so they can use the smallest possible wire. I have seen 16 gauge wire on a 20 amp circuit. They calculate that it is a 2 foot cable run and powers something that is not affected by a voltage drop. Or a lighter that is only operated for a short period of time. Constant duty items like the heater motor still get 10 gauge wire.
