Menu
Forum
What's new
New posts
Live Activity
Search forums
Members
Registered members
Classifieds Member Feedback
Car Audio Discussion
General Car Audio
Car Audio Build Logs
Car Audio Equipment
Subwoofers
Speakers
Amplifiers
Head Units
Car Audio Help
Wiring, Electrical and Installation
Enclosure Design & Construction
Car Audio Classifieds
Car Audio Classifieds
Car Audio Wanted
Classifieds Member Feedback
Gallery
New media
New comments
Search media
SHOP
Shop Head Units
Shop Amplifiers
Shop Speakers
Shop Subwoofers
Shop eBay Car Audio
Test
Forum
Search
Search titles only
Search titles only
Log in / Join
Search
Search titles only
Search titles only
What's new
New posts
Live Activity
Search forums
Members
Registered members
Classifieds Member Feedback
Menu
Reply to thread
Forum
Car Audio Help
Wiring, Electrical & Installation
Bet this will stump everyone!!!! voltage disappears when head unit plugged in.
JavaScript is disabled. For a better experience, please enable JavaScript in your browser before proceeding.
You are using an out of date browser. It may not display this or other websites correctly.
You should upgrade or use an
alternative browser
.
Message
<blockquote data-quote="2004tundra" data-source="post: 8741344" data-attributes="member: 682704"><p>So I have a 2004 toyota tundra SR5 4x4 4.7L. It had the stock head unit in it which consisted of a CD player and cassette deck in a single, double din head unit. Since I'm not really a big car audio enthusiast and this is my work truck, I never changed it out. I decided to buy one of those Chinese "Konifo" double din head units from amazon <a href="https://www.amazon.com/dp/B08V1HJKB8/?tag=caraudiocom-20" target="_blank">https://www.amazon.com/dp/B08V1HJKB8/?tag=caraudiocom-20</a> . When I hook it directly to a 12v battery, it powers up right away, so I know it works. I have the service manual for this model truck so I have the wiring diagrams. In the stereo wiring from the truck there is only one ACC wire and one constant 12V wire. Radio ground wire is the brown wire. Hooking the volt meter to the constant 12v wire reads 11.6v with the engine off and 12.65v when running. The ACC wire reads 0 volts with key in off position , 11.6v with key in ACC position and 12.65v when running (with the black lead of the volt meter on the brown ground wire) Connect the head unit and the voltage disappears completely from the ACC wire and drops to 1.9volts on the constant voltage wire. Is it possible the truck's computer senses something other than the factory head unit and kills the voltage to these wires? I have never read about another 04 Tundra doing this. I checked this again and again, unplug the harness from the head unit, insert probes into the harness, back up to normal voltage, plug the unit unit back in, voltage disappears, unplug and connect directly to 12v battery and it powers right up again. Has anyone experienced this? I think if I ask anyone , they wont believe its really doing this, it doesn't even seem scientifically possible.</p></blockquote><p></p>
[QUOTE="2004tundra, post: 8741344, member: 682704"] So I have a 2004 toyota tundra SR5 4x4 4.7L. It had the stock head unit in it which consisted of a CD player and cassette deck in a single, double din head unit. Since I'm not really a big car audio enthusiast and this is my work truck, I never changed it out. I decided to buy one of those Chinese "Konifo" double din head units from amazon [URL]https://www.amazon.com/dp/B08V1HJKB8/?tag=caraudiocom-20[/URL] . When I hook it directly to a 12v battery, it powers up right away, so I know it works. I have the service manual for this model truck so I have the wiring diagrams. In the stereo wiring from the truck there is only one ACC wire and one constant 12V wire. Radio ground wire is the brown wire. Hooking the volt meter to the constant 12v wire reads 11.6v with the engine off and 12.65v when running. The ACC wire reads 0 volts with key in off position , 11.6v with key in ACC position and 12.65v when running (with the black lead of the volt meter on the brown ground wire) Connect the head unit and the voltage disappears completely from the ACC wire and drops to 1.9volts on the constant voltage wire. Is it possible the truck's computer senses something other than the factory head unit and kills the voltage to these wires? I have never read about another 04 Tundra doing this. I checked this again and again, unplug the harness from the head unit, insert probes into the harness, back up to normal voltage, plug the unit unit back in, voltage disappears, unplug and connect directly to 12v battery and it powers right up again. Has anyone experienced this? I think if I ask anyone , they wont believe its really doing this, it doesn't even seem scientifically possible. [/QUOTE]
Insert quotes…
Verification
Post reply
Forum
Car Audio Help
Wiring, Electrical & Installation
Bet this will stump everyone!!!! voltage disappears when head unit plugged in.
Top
Menu
Home
Refresh