18 gauge wire from battery

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TF360

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Is it ok to run a 18 gauge wire directly from my battery to my stereo. It's not the main power wire that comes on with the ignition. I believe it's to run the clock and maybe presets. I would rather not splice into a factory wire. Thanks
 
That is not advisable, I'd get it at the starter relay or inside.


Alan
 
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That's super thin to be running that far of a distance. My answer is NO!
 
No matter where you pick up power, put an inline fuse as close to the source as possible, and yea 18 ga is kinda lite, go 14
 
True. The heavier gauge of wire that you use, the less resistance and heat the wire will see. And you should run from a fused power supply. Go to the bulkhead fuse block and tap into the fused side of the radio fuse connection. Or any other keyed connection if no radio fuse. 14 gauge would work fine. Clean and dielectric grease all electrical connections.
 
You could also tap into the fusebox. The yellow (constant power) wire is also the main power for the radios internal amplifier, so it can draw 8-9 amps of current. If you run it to the battery, it should be at least 14 gauge wire fused with a 10 amp fuse, within a few inches of the battery. The red (switched power) wire can be fused with a 2 amp fuse.
 
Garry in AZ said:
You could also tap into the fusebox. .
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That is exactly what I'd do. There are two busses in the rear of the fuse panel. One is hot all time, one is switched "accessory" by the ignition. Put about a 1-2A fuse inline from that
 
MoparLeo said:
Remember that if you don't go switched, it will continuously draw power. Better to be switched and safer.
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These don't draw much, on the order of milliamps. All they do is hold the radio memory.
 
Just an FYI Of course we don't know anything about his stereo system. Amplifiers/ amperage draw on system ? Quality of components ? Install quality ? How long car can sit between usage ? Condition of the cars electrical system ? They were marginal when new. 40-60 amp alternators, mechanical voltage regulators, light gauge wiring, marginal connectors....
Here are some recommended electrical articles to help understand the electrical system on our Mopars and how to update/improve them.
Vintage Chrysler electrical repairs and updates
Vintage Chrysler electrical repairs and updates (part 2)
Improved Wiring for older Mopars
Fixing Dim Or Blinking Headlights - Quick Tech - Mopar Muscle Magazine
Catalog
 
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Short answer -yes. IF that is the size coming out of the radio it would be fine to continue with that to a power pickup point. Even for 18, you are only going to have a fraction of an ohm if you ran the entire length of the car. That said, I usually run the next size up. If its got 18 coming out of the radio, I would go with 16. Fuse it at least to protect the 18 (like 5A), but could prob do lower 1-2 amp if its just a memory or even a backlight circuit. Your not likely to ever overdraw on a circuit like that, really doing it in case of a short. I wouldn't go to the battery, that gets sloppy looking.
 
Fellas, I feel like I need to explain this better... based on the following assumptions:
I assume this is a typical aftermarket radio, and typical aftermarket radio wiring. (Kenwood, JVC, Sony, Alpine, Pioneer, Clarion, Jensen, Dual, Blaupunkt, Soundstream, et al)
I assume the speakers are being driven by the radio, not an external amplifier.
If these assumptions are correct, there will be a yellow wire for constant power, and a red wire for switched power coming out of the radio.
ALL aftermarket radios use the YELLOW wire to provide the current for the internal amplifier that drives the speakers. This wire also provides a constant power for the memory functions, and the ability to operate certain functions when the key is off. (Ejecting a CD for example)
This means that the yellow wire will need at least a 10A fuse to properly power the radios internal amplifier. The yellow wire is NEVER just for memory functions. You can prove this for yourself if you connect an ohm meter from the yellow wire to the radios chassis mounted main 10A fuse. If you put a 2 or 5 amp fuse in this lead, the draw from the internal amp will blow it.
The RED wire is simply used to turn the radio on and off with the vehicles ignition, and is a low current draw connection. (less than 1 amp)

I'm absolutely certain of the above statements, if the stated assumptions are true. Engineering audio products is what I do for a living, and I test dozens of radios every year.
 
Garry in AZ said:
Fellas, I feel like I need to explain this better... based on the following assumptions:
I assume this is a typical aftermarket radio, and typical aftermarket radio wiring. (Kenwood, JVC, Sony, Alpine, Pioneer, Clarion, Jensen, Dual, Blaupunkt, Soundstream, et al)
I assume the speakers are being driven by the radio, not an external amplifier.
If these assumptions are correct, there will be a yellow wire for constant power, and a red wire for switched power coming out of the radio.
ALL aftermarket radios use the YELLOW wire to provide the current for the internal amplifier that drives the speakers. This wire also provides a constant power for the memory functions, and the ability to operate certain functions when the key is off. (Ejecting a CD for example)
This means that the yellow wire will need at least a 10A fuse to properly power the radios internal amplifier. The yellow wire is NEVER just for memory functions. You can prove this for yourself if you connect an ohm meter from the yellow wire to the radios chassis mounted main 10A fuse. If you put a 2 or 5 amp fuse in this lead, the draw from the internal amp will blow it.
The RED wire is simply used to turn the radio on and off with the vehicles ignition, and is a low current draw connection. (less than 1 amp)

I'm absolutely certain of the above statements, if the stated assumptions are true. Engineering audio products is what I do for a living, and I test dozens of radios every year.
Click to expand...

No kidding?
Didn't know that, thank you.
I have my memory/ and apparently the stereo's internal amp running of my lighter circuit, but it must be capable due to what a lighter draws.
I have used the lighter with the stereo playing without blowing the fuse, so it must be capable.
And to think all these years I thought the red wire carried the amp loads.:D
 
Garry it's a 1980's Kenwood am/fm cassette. There is already a little fuse box factory installed for the red and yellow wires. The red is hooked up, but I'm going to look for a place to connect the yellow too. What would you recommend? 1974 Plymouth Duster- Thanks for all the input
 
..............An 18 ga. wire is not gonna be a main power feed, juz' sayin........
 
Connect the yellow wire to a terminal in the fuse box that is hot all the time. Dome light, cigarette lighter, headlight circuits. All you need is a constant power connection that will allow an 8-10 amp draw.

67Dart273...... actually, on modern aftermarket radios, the main power feed wire is 18 gauge, and sometimes even as small as 20 gauge, but it's only 6 inches long. They expect it to be spliced into the cars original harness right at the back of the radio. I think the wire is too small too, but it's really what is being used these days.
The other thing to know is, although most aftermarket radios advertise 40, 50, or even 100 watts per channel on the box, in actuality there are no radios that make more than about 18 watts per channel. That's how they can get away with only a 10A fuse.
 
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