2008 Vellfire FM Aerial issue

[Monkins]

Hi all, Bought a 2008 Vellfire couple of weeks ago and the dealer had fitted an android 9" touchscreen, and replaced the flip down TV in the rear with an xtronics one..  The FM signal is trash, I have done some investigating and the rear offside window has the FM amplifier module in there and I found that the little black cable on pin 5 on the radio goes to the FM Amplifier so i joined it to the PIN 1 ignition to power the amp.  Still trash reception.  I then tried disconnecting the connector on the aerial amp itself and the radio still plays radio albeit no change and still crap.  So i then tried to test with a multimeter to the centre of the coax cable in the cable running to the FM amp  to the DIN style aerial socket behind the Radio, im not getting continuity? SO what's happening? I fear I'm going to have to trace the cable and see if its broke somewhere, if it is i cant see how its getting any signal to the radio.  Or has someone been tinkering and put an aerial in the roof liner or something daft?

 

Any ideas would be welcome. 

 

thanks, Chris

[Rojie]

8 hours ago, Monkins said:

Hi all, Bought a 2008 Vellfire couple of weeks ago and the dealer had fitted an android 9" touchscreen, and replaced the flip down TV in the rear with an xtronics one..  The FM signal is trash, I have done some investigating and the rear offside window has the FM amplifier module in there and I found that the little black cable on pin 5 on the radio goes to the FM Amplifier so i joined it to the PIN 1 ignition to power the amp.  Still trash reception.  I then tried disconnecting the connector on the aerial amp itself and the radio still plays radio albeit no change and still crap.  So i then tried to test with a multimeter to the centre of the coax cable in the cable running to the FM amp  to the DIN style aerial socket behind the Radio, im not getting continuity? SO what's happening? I fear I'm going to have to trace the cable and see if its broke somewhere, if it is i cant see how its getting any signal to the radio.  Or has someone been tinkering and put an aerial in the roof liner or something daft?

 

Any ideas would be welcome. 

 

thanks, Chris

 

Hello Chris,

 

Welcome to the Forum.

[Monkins]

https://rennlist.com/forums/928-forum/579218-purpose-of-resistor-in-coax-antenna-wire.html Reading this thread it looks like the coax plug may have an inline capacitor in the centre to block DC. So this may be the reason of the no continuity. I will take the trim off the A pillar and disconnect it at the connector and test it there.