Fitting new radio in T4 Caravelle

[vk2mad]

Hi all. I removed the old radio and fitted a new jvc radio. My problem is that whilst F.M.works well, A.M. is almost non existent. I believe that a booster is fitted and that 12v has to be fed up the coax to power it. When I connect the 12 v across the coax it makes A.M. even worse, if that were possible. I am really puzzled as to what is going on. Any thoughts? Jim

[Sunny43.5]

If my memory serves me well my sons old 97 T4 has only a conventional mast type antennae running up the windscreen pillar , I don't recall when I fitted a fold out screen multi media head unit ever needing to connect power to the antennae . Am is pretty hard to get these days although my latest one in my T5 which is an android system pulls in the Am pretty good in comparison to our older units from the past . The thing to look for is the antennae connector a single pole type on its own with no other wires if so then I doubt its powered . Most modern head units have a power wire to connect to an antennae IF IT is powered I would suggest to trace the aerial wire back to the base and see if there is a booster in line .

[vk2mad]

It is funny how the old radio was great on A.M., but not the new one. I will turn into a contortionist and trace the cable. Jim

[Sunny43.5]

Seems to be a VW thing , I did check once with an audio shop on what they did with VW's and they told me they had similar problems . NOW they did point out that this mainly applied to 2004 onwards VWs , they use a test lamp with one end connected to a 12v source they then probe each wire in the original loom for the radio until they get the one which powers up the antennae then connect that one to a 12v source from the head unit [usually a blue wire called Pcon ]. Now I tried this with my t5 van and no luck but it apparently works with other vw models maybe worth a try just in case there is a power for the antennae . With our two T5s we fitted a roof mount antennae from Auto Barn it is for a Nissan X Trail and is powered . It did help but still not much improvement to AM as I said earlier the latest one I just fitted is an Android OS and the AM was massively improved we never used to be able to get AM where we live which is 40kays out of Brisbane .

[vk2mad]

I bit the bullet and fitted an in line amplifier in the coax behind the radio. Problem solved, although I don't know how the old radio worked so well