From all I have read it seems it is recommended to wire mobile radios to direct to the battery, and it is said to wire the ground directly too to prevent any interference. I want my radio turned off when the truck is off, so I was going to use a relay for this, doesnt seem that many people go this route, is there an interference issue with relays as well?
Wiring
- Thread starter N / A
- Start date
unusedusername
Observer
A mechanical relay won't cause issues as long as your radio is OK with having the power shut off out from under it.
I've got a Uniden scanner that runs off a SD card. It tends to corrupt the SD card if I unplug it while it is on.
I've got a Uniden scanner that runs off a SD card. It tends to corrupt the SD card if I unplug it while it is on.
prerunner1982
Adventurer
It will work, but may I ask your reasoning?
A radio on receive won't draw enough to drain your battery and being able to turn the radio on without having to turn on the vehicle can be nice.
A radio on receive won't draw enough to drain your battery and being able to turn the radio on without having to turn on the vehicle can be nice.
pugslyyy
Expedition Vehicle Engineer Gal
Yeah I actually like being able to leave my radios on when on the trail but out of the vehicle.
brentbba
Explorer
This! ...and I have both truck and commuter car radios wired direct to the battery with 15 amp fuses on both positive and negative wires at the battery.
Why on both wires?
Short protection. 857d draws about 1/2 amp, a little more when actually receiving a transmitted signal. It is hardwired to 2nd battery circuit, but not right to the battery. If you have a radio with APRS, then you might want an auto-shutoff circuit, so when you turn off the truck, the power goes off.
The PWR Guard plus might do the job.
https://powerwerx.com/fuses-circuit-protection
The PWR Guard plus might do the job.
https://powerwerx.com/fuses-circuit-protection
Last edited:
pugslyyy
Expedition Vehicle Engineer Gal
Maybe he had an extra? But seriously, no, don't do that. If for some reason the fuse blows it just loses the direct ground and will have to rely on the chassis ground.
Cool web site pugslyyy
This is a hotly debated topic I guess. I did it with both fuses, radio also comes that way. Installer preference will prevail. OALAEGOATAS
http://www.arrl.org/forum/topics/view/115
Should I add a fuse on the negative lead from 9-120AH battery?
Mobile radio installs - should I run the negative lead from radio to chassis, or to battery? should it be fused or not?
(Most mobile radios include a fuse on both positive and negative leads - I think this a holdover from years ago when commercial installs used positive ground radios so included a fuse on negative
lead, not knowing what type of vehicle it might be installed in).
I'll clarify my post, and explain further. I have a 75 amp run from the engine compartment to the rear of the vehicle. Both Positive and Negative are fused AT THE BATTERY on that line. If there is a short to body or another ground, to the positive the fuse will blow at the battery, to reduce the chance of a fire. The fuse on the Negative would do the same thing, which is protect the ground, if a short developed from a hot line to the ground.
The Ham Radio I'm using has both fuses in the factory cable. Picture of power cord here.
http://www.radiospecialists.com.au/Radio Power cables.htm
This is a hotly debated topic I guess. I did it with both fuses, radio also comes that way. Installer preference will prevail. OALAEGOATAS
http://www.arrl.org/forum/topics/view/115
Should I add a fuse on the negative lead from 9-120AH battery?
Mobile radio installs - should I run the negative lead from radio to chassis, or to battery? should it be fused or not?
(Most mobile radios include a fuse on both positive and negative leads - I think this a holdover from years ago when commercial installs used positive ground radios so included a fuse on negative
lead, not knowing what type of vehicle it might be installed in).
I'll clarify my post, and explain further. I have a 75 amp run from the engine compartment to the rear of the vehicle. Both Positive and Negative are fused AT THE BATTERY on that line. If there is a short to body or another ground, to the positive the fuse will blow at the battery, to reduce the chance of a fire. The fuse on the Negative would do the same thing, which is protect the ground, if a short developed from a hot line to the ground.
The Ham Radio I'm using has both fuses in the factory cable. Picture of power cord here.
http://www.radiospecialists.com.au/Radio Power cables.htm
Last edited:
If you ground directly to the battery and the main negative cable to the vehicle comes loose then the entire vehicle will try to "ground" from your antenna mount, down the coax, thru the body of the radio, and thru it's negative lead. You don't want this to happen. A fuse in the negative lead prevents this. Or, grounding near the battery on the chassis right where the main factory negative lead grounds get's you a direct connection but doesn't put the radio in "parallel" with the main negative lead if it comes undone.
pugslyyy
Expedition Vehicle Engineer Gal
Okay.
Similar threads
