New Head Unit install, the blue wire?

mattsrav4 · Jul 13, 2018

Installing a new head unit in my 2012 RAV4 - it's a Kenwood DNX572BH if that means anything. Anyway, the new head unit has a blue wire on the main wire harness, for the power antenna. There is also a blue wire in the wiring adapter kit I purchased, the Crux SWRTY-61N (found here - https://www.amazon.com/gp/product/B01BM3QGCO/ref=oh_aui_detailpage_o09_s00?ie=UTF8&psc=1). That wiring adapter kit also included an "antenna adapter", which itself also has a blue wire.

What gets connected to what? All three together? Just the one from the head unit directly the the adapter?

Thanks!

Rav4system3 · Jul 13, 2018

If I remember correctly the blue wire powers the factory antenna. So if it is not hooked up your radio reception will be terrible. When I did mine I connected the blue wire from the radio to the blue wire in the new wire harness. I did not use the harness you have, but it should be the same.

mattsrav4 · Jul 13, 2018

Yes, the blue wire is for the power to the factory antenna - that much I know. It's just that I have 3 of them. One from the head unit - one in the wire harness (I'll track that wire down to see where it goes to on the other end) and then one in the antenna adapter. So do I just hook all three together? I guess I can just try a few different things till I have really good reception.....

mattsrav4 · Jul 16, 2018

For anyone reading this in the future - connect the blue antenna power wire from the head unit directly to the antenna adapter blue wire. The blue wire that was in my wiring harness adapter didn't connect to anything on the car's 28 pin harness, so there was no point connecting that.

Next item - where is the reverse wire on these things? Needs to connect the reverse wire of head unit to vehicle somewhere so that when car is in reverse, rear view camera comes up. Thanks.

JuneBug · Jul 16, 2018

Pry open this fuse box cover to the left of the steering column:

And use the red wire for your reverse trigger:

mattsrav4 · Jul 18, 2018

JuneBug said:
Pry open this fuse box cover to the left of the steering column:

And use the red wire for your reverse trigger:

Great stuff, thanks! So the reverse wire from headunit gets tapped into that wire you're pointing out. Then the RCA video cable from the head unit goes via video cable back to camera itself. The camera also has two small wires - one red and one black. I assume the black is ground, so no issue there - the red is power. Should that wire get "constant power" or just power when the reverse light itself gets power? My HU allows for viewing of rearview camera anytime (not just in reverse), so where should the small red wire in my camera kit be connected to?

JuneBug · Jul 19, 2018

mattsrav4 said:
The camera also has two small wires - one red and one black. I assume the black is ground, so no issue there - the red is power. Should that wire get "constant power" or just power when the reverse light itself gets power? My HU allows for viewing of rearview camera anytime (not just in reverse), so where should the small red wire in my camera kit be connected to?

I have no idea, what does the documentation say? You might just need to experiment a bit.

rav42018 · Sep 23, 2018

Thank you for this post. On our 2018 RAV4 we used the CRUX SWRTY-61N kit and there is a blue wire on the antenna that must be connected to the new head unit. In my case, the head unit is a Pioneer AVH-2440NEX and the head unit 'antenna power' wire is blue/white and labeled with a sticker that indicates the wire can be used for 'system remote' However the Pioneer manual says 'connect to external power amps system remote control or the antenna booster power control terminal (max 300 ms, 12 V DC). Hope this helps.

Gaals9999 · Oct 11, 2018

hello, I have the ROSEN upgrade radio/nav unit that came with the car when I bought it used. the blue wire for the antenna is connected to another wire from the factory harness with a tap. I have almost NO radio reception. Is the blue wire supposed to get power? Ground? I cannot find it in the schematic, only a generic wire. Also, where physically is the antenna amp located? The antenna wire/blue wire disappear into a harness under the dash.
Thanks for any help!

t0ere · Oct 12, 2018

A blue wire is typical for a remote turn on, like an external amplifier or a powered antenna. It will bring 12v when the key is turned on but it's not feeding the radio signal. The antenna cable is a coaxial cable that plugs directly to the head unit and it's a rather thick and black. If you don't see it on the back of your unit, that explains why you don't get any signal. Look for the antenna cable if it has not fallen inside the cluster.

Sent from my SM-G935F using Tapatalk

mitaraho · Jul 8, 2022

t0ere said:
A blue wire is typical for a remote turn on, like an external amplifier or a powered antenna. It will bring 12v when the key is turned on but it's not feeding the radio signal. The antenna cable is a coaxial cable that plugs directly to the head unit and it's a rather thick and black. If you don't see it on the back of your unit, that explains why you don't get any signal. Look for the antenna cable if it has not fallen inside the cluster.

Sent from my SM-G935F using Tapatalk

This was my question, sort of... I don't think I have a standard antenna plug on my Kenwood head unit and I don't remember seeing the cable in the cluster but it's been 2 years since I've had it apart and I've been running with no radio for that long and now I need it for an outdoor theater audio reception. I thought the antenna was a plug and I do remember bending a thin pin in the plug which I thought was my reason for poor/no reception but after reading this thread I'm not sure what the antenna cable is and it's midnight and I'm itching to tear apart the dash and figure this out and McGuiver a way to straighten the pin with needle nose pliers and tweezers.

Any advice would be appreciated, I'm off to tear it apart!

mitaraho · Jul 8, 2022

mitaraho said:
This was my question, sort of... I don't think I have a standard antenna plug on my Kenwood head unit and I don't remember seeing the cable in the cluster but it's been 2 years since I've had it apart and I've been running with no radio for that long and now I need it for an outdoor theater audio reception. I thought the antenna was a plug and I do remember bending a thin pin in the plug which I thought was my reason for poor/no reception but after reading this thread I'm not sure what the antenna cable is and it's midnight and I'm itching to tear apart the dash and figure this out and McGuiver a way to straighten the pin with needle nose pliers and tweezers.

Any advice would be appreciated, I'm off to tear it apart!

Update. I went and tore apart the dash and head unit. Yes there's a thick black coax style cable plugged firmly into the back of the Kenwood. On the same cable there's a plug with a blue wire like you said. Blue wires are firmly connected and capped and torqued with an electrical nut. Tightest connection I could make. Only other thing I did was gently put my needle nose pliers in the plug and straighten the small pin that was slightly bent. Reconnected the cable with a firm tightness. Nothing is loose or disconnected.

FM signal is working but the connection isn't the greatest, the OEM head unit sounded MUCH clearer. What truly baffles me is I don't have any AM signal whatsoever. No idea how or why that's possible.

Any ideas?

seabird · Aug 8, 2022

mattsrav4 said:
For anyone reading this in the future - connect the blue antenna power wire from the head unit directly to the antenna adapter blue wire. The blue wire that was in my wiring harness adapter didn't connect to anything on the car's 28 pin harness, so there was no point connecting that.

Next item - where is the reverse wire on these things? Needs to connect the reverse wire of head unit to vehicle somewhere so that when car is in reverse, rear view camera comes up. Thanks.

this post was very helpful in my situation.

i bought an aftermarket android head unit and i couldn't figure out why the radio reception was so poor. the antenna was connected and the wire harness that came with the head unit had a blue cable so i assumed it was all connected properly.

i haven't done this yet, but will be connecting the blue cable from the antenna directly to the blue cable from the main wire harness to see if this fixes my issue. i suspect the blue cable in the antenna wire harness is connected to nothing.

will report back to see if it worked.

thanks

mitaraho · Aug 8, 2022

seabird said:
this post was very helpful in my situation.

i bought an aftermarket android head unit and i couldn't figure out why the radio reception was so poor. the antenna was connected and the wire harness that came with the head unit had a blue cable so i assumed it was all connected properly.

i haven't done this yet, but will be connecting the blue cable from the antenna directly to the blue cable from the main wire harness to see if this fixes my issue. i suspect the blue cable in the antenna wire harness is connected to nothing.

will report back to see if it worked.

thanks

I had the exact same issue and this is the problem and how I fixed it. The problem is the antenna on the back of the roof has an amplifier in it and unless you send power back to the amplifier you'll get poor to no reception in my case.

My solution was yes, connect both of the solid blue wires which I had already done and it still didn't work, so I took the blue wire with a white stripe (should be labeled pwr antenna or accessory) and tie this wire into the two solid blue wires. Instantly had reception and AM finally worked.

Hope this helps,
Tim

New Head Unit install, the blue wire?

mattsrav4

Rav4system3

mattsrav4

mattsrav4

JuneBug

mattsrav4

JuneBug

rav42018

Gaals9999

t0ere

mitaraho

mitaraho

seabird

mitaraho

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