2011 Isuzu dmax radio aerial

Submitted: Sunday, Dec 01, 2013 at 13:42

ThreadID: 105331 Views:6574 Replies:1 FollowUps:9

This Thread has been Archived

Bill2584

I am hoping someone will be able to shed some light on this puzzle.

I have installed a double din Sony head unit everything works perfect except for am radio, fm is pretty awful as well. I have an external aerial and bench tested the Sony unit it gets perfect radio reception so it has to be the aerial in the truck anyone had anything like this before.

Note: Factory radio gets perfect reception with factory aerial

Thanks for any thoughs or tips.

Will

Back Expand Un-Read 0 Moderator Share

Reply By: Ross M - Sunday, Dec 01, 2013 at 15:50

Sunday, Dec 01, 2013 at 15:50

G'day Will

I'm not sure where the power comes from, never has to fully investigate, but, the 2011 Isuzu Dmax has an aerial amplifier at the roof, just under the aerial base itself.
It is powered when the radio is used and with the fitting of the NEW gear you may not have the power to the aerial amp connected or powered anymore.

If it is switched on by the radio, the wire possibly hasn't been noticed and/or connected or something you have done has either blown a fuse for the amp if there is one. Again I haven't looked.

Because the factory radio works with the factory aerial it points to the fact that one of it's connections is the +12v provider which the newy hasn't got or isn't connected.
The aerial up/down wire on the new one may be the wire you have to use.

Cheers
Ross M

AnswerID: 522416

Follow Up By: Bill2584 - Sunday, Dec 01, 2013 at 16:41

Sunday, Dec 01, 2013 at 16:41

Cheers Ross.

I tried to find amp power when the old unit was plug in but I couldn't find any in the 3 un used wires. I'll try again wiring diagrams are hard to come by on the internet.

Cheers Will

FollowupID: 803485

Follow Up By: Nomadic Navara - Sunday, Dec 01, 2013 at 16:53

Sunday, Dec 01, 2013 at 16:53

Could be that the amplifier power is fed up the co-axial cable just like TV mast head amps get their power.

PeterD
Retired radio and electronics technician

Lifetime Member
My Profile Send Message

FollowupID: 803486

Follow Up By: Bill2584 - Sunday, Dec 01, 2013 at 17:02

Sunday, Dec 01, 2013 at 17:02

Ah well that's unfortunate only option is to put a new aerial in then?

FollowupID: 803488

Follow Up By: Ross M - Sunday, Dec 01, 2013 at 18:41

Sunday, Dec 01, 2013 at 18:41

Not sure about amp power but aerial power maybe.

Have a look at the aerial base to see if it has an external power feed or uses the coax as Peter mentioned.
If coax powered, he may be able to suggest a method of using a decoupler or similar. That is his field of expertise. I thought it had it's own power supply though.
I saw a picture of one and it appeared to have it's own circuit board at the base.

You may be able to access the underside by removing the interior light unit to see wire colours etc.

It's either one or the other.

FollowupID: 803496

Follow Up By: Nomadic Navara - Sunday, Dec 01, 2013 at 19:34

Sunday, Dec 01, 2013 at 19:34

Ross, I only said "could be" as I have not had any experience on them for over 20 years. Back in those days the only thing that car radios provided power for was extensible antennas.

PeterD
Retired radio and electronics technician

Lifetime Member
My Profile Send Message

FollowupID: 803500

Follow Up By: Bill2584 - Sunday, Dec 01, 2013 at 19:35

Sunday, Dec 01, 2013 at 19:35

Thanks guys,

We are getting somewhere I have found a continuous wire from the aerial to the connector what sort of voltage should go into it?

FollowupID: 803501

Follow Up By: Bill2584 - Sunday, Dec 01, 2013 at 19:49

Sunday, Dec 01, 2013 at 19:49

Scrap that I thought it was but not same colours though

FollowupID: 803503

Follow Up By: Ross M - Sunday, Dec 01, 2013 at 19:59

Sunday, Dec 01, 2013 at 19:59

Well found.

I would think the wire is fed with 12v via the radio output ie aerial up down as mentioned.
Surely you can test it with the old radio and see what voltage is in the wire. That should then ensure you have it correct.

If in doubt I would connect power to the wire but first have it pass through a small globe ie 10W globe.
If the aerial unit uses a small amount of power, very low current, the voltage on the aerial side of the globe will be nearly 12v and it will possibly glow and the unit will operate and amplify the signal.

If for some reason it demands a high current, (unlikely), then the globe will shine bright because of the current flow being used. Can't see this happening though.
If it all runs with the globe in the line then remove it, the globe, and connect aerial booster wire to the new audio's aerial up/down power wire.
"Problem Solvered".

Let us know how you get on for reception.

FollowupID: 803504