No am reception with aftermarket stereo? Need 12v to antenna amp.

[cohocarl]

After I installed my Panasonic H.U. just after I got the car almost a year ago, I noticed I didn't have any AM reception. FM reception was o-tay, but not spectacular. I had read some posts about you need to run power to the Vibe's built in antenna amplifier. The stock radio feeds the 12V needed through the wiring harness that attaches to the rear of the radio, but aftermarket wiring harnesses don't have this lead. I don't listen to am that much, so I didn't pay attention. About a foot back from the end of the antenna lead that goes into the rear of your radio is a black wire that runs along the antenna lead. It then goes into a wiring harness with many other wires.Along this black wire is a white quick-disconnect that also has a piece of foam wrapped around it. I disconnected this white connector and cut back about 5 inches of the loosely fitting shrink-wrap type plastic that is around the wire. (to the left of the connector) (between the connector and where it meets the wiring harness)I then snipped the wire about 2 inches past the white connector so it would leave me enough wire to be able to strip the insulation and wire it into the 12V accessory (red) wire leading into the radio. You want to tap into the accessory lead, not the "always on" 12V lead.I taped everything back up (including the other end that was cut, coming out of the wiring harness), plugged the connector back into the lead that runs along the antenna lead, and that's it.There was a post on Matrixowners that told you how to do it, but he cut the wire on the right side of the white connector to splice it in. I put it on the other side of the connector so I still have quick disconnects on all the connections going to the radio.Great FM and AM reception now!Sorry I didn't take any pics. I need to yank the radio out in the next couple days again anyways to try and splice in a lead off of the antenna to feed the tv tuner in my dvd player to see how it works. I'll take a pic then and post.Later,Carl

[joatmon]

Some radios have an output for a power antenna, Turn the radio on and the antenna goes up. If a radio had such a signal, couldn't it power the antenna amplifier?

[cohocarl]

quote:If a radio had such a signal, couldn't it power the antenna amplifier?That's an excellent idea! Didn't think of that.

[NSimkins]

quote:Some radios have an output for a power antenna, Turn the radio on and the antenna goes up. If a radio had such a signal, couldn't it power the antenna amplifier?Just installed an aftermarket Kenwood receiver - I ended up doing exactly what cohocarl did with the antenna power wire but I did have a "Power Antenna" lead from the HU wire harness that I used - I also checked with the techs at Crutchfield and they verified this was accurate as well.Either way, my reception is normal, if not better than the stock unit after doing this.

[ragingfish]

So you're saying connecting that little harness to +12V will improve my radio reception?

[cohocarl]

Quote, originally posted by ragingfish »So you're saying connecting that little harness to +12V will improve my radio reception?If you've put in a different h.u. and the antenna amp isn't receiving power, yes it will give you better reception. I had NO AM stations before I hooked it up and have tons of them now. FM improved also, but not as drastically.Can you receive many am statios now?

[ragingfish]

Yeah, I get them, but the quality of the signal is fair at best. Even my FM has an unusual amount of interference in my opinion...

[Jahntassa]

I would go with the idea of connecting that wire to switched power..NOT the antenna-turnon (blue) from the headunit! The antenna turn-on wire does NOT put out a lot of voltage, merely enough to tell most power antennas to put themselves up. Our antenna, which is powered, probably needs more voltage than that circuit can put out.Though, I had always thought the antenna power was connected elsewhere in the car..never bothered to trace that wire (paired with the antenna) to see where it went...

[ragingfish]

Not sure if this helps you electronics buffs figure out how it all works...but the antenna amp is up in the right corner.Interestingly enough, I think I discovered that the antenna amp normally gets it's power from the B3 pin in the harness with a stock HU. Since that's the same pin used to send the amplifier turn-on signal, perhaps it should be connected to +12 instead of just a remote signal...hmmm....

Attached files

[hax3]

Quote, originally posted by cohocarl »Along this black wire is a white quick-disconnect that also has a piece of foam wrapped around it. I disconnected this white connector and cut back about 5 inches of the loosely fitting shrink-wrap type plastic that is around the wire. (to the left of the connector) (between the connector and where it meets the wiring harness)I then snipped the wire about 2 inches past the white connector so it would leave me enough wire to be able to strip the insulation and wire it into the 12V accessory (red) wire leading into the radio. There was a post on Matrixowners that told you how to do it, but he cut the wire on the right side of the white connector to splice it in. I put it on the other side of the connector so I still have quick disconnects on all the connections going to the radio.FYI: I tried to do exactly what you did but it did NOT work for me - not sure if it's cuz of a different HU (JVC) or a different year (base 05 vi be)... anyway, to make it work for me I used the other (RIGHT) side of the black wire - the one with the foam.. I cut the white quick disconnect female jack with the foam and connected it to the blue/white cable from the back of the HU.. works like a charm.. anyway.. just thought I post my experience in case others have the same problem..

[Dj_kulture]

Hey... I just replaced my factory with an aftermarket kenwood. And the AM reception SUCKS. I checked this forum, and I had not connected the power antenna wire to the harness (I didn't think I needed it since the antenna isn't powered like a retractable one) finding out it has an amp.. i hooked it up to the power ant. wire (blue white) on the stereo... but the am reception still sucks, (fm is fine) but there is one AM station I listen to a lot for news and talk....so the question is... would hooking the ant power wire from the vibe, to the +12 switched wire (red) improve performance? is the output of that wire, that much more than the ant power wire (blue/white?) the station just goes in and out so much more than it did with the factory radio. sounds like lots of electrical interference too.

[kitep]

7 years later and your post is still relevant. I installed an aftermarket radio and had FM but no AM reception. Finding the power radio wire and connecting it to the +12 ACC power line fixed everything.Thanks!

[misterT]

my reception improved remarkably. Went from getting no channels to channels I've never been able to get before. Thanks!!

[Petrus4]

I don't have an aftermarket radio but have the same symptoms. I have am/fm/satelite/cd but can get no am reception, when I scan for fm channels I only get a one or two when in certain locations otherwise I have to manually enter them. The reception is worse than that my old Honda Civic 97 or Saturn L200 2001

This applies to a Pontiac Vibe 2009 with am/fm/cd and satelite stock radio.

I also noticed that fuse # 30 which is listed as "AMP" is missing. I replaced it but this did not do anything.

Does anyone have an idea what could be wrong?