Intermittent radio reception

[PC2CV]

A problem with my 607
The radio reception as I drive along seems to go fuzzy and it becomes unable to find any stations, yet when I turn the engine off it seems to be able to pick stations up again.

I have noticed the headlights flicker with the engine revs, particularly noticeable when changing gear, could this be a problem associated with an alternator on the way out?

[Stickyfinger]

UN plug ALL accessory power adapters....try that first

not a clue about the light other than check all power and earths for the lights.

[PC2CV]

I have no power adapters or any other features plugged into the car.

Noticed this morning that after starting the car the radio worked, turned on the heated rear window and the radio went fuzzy.

I think the alternator is on the way out, the heater blower seems to speed up and slow down with engine revs now aswell.

[white exec]

Think I remember reading somewhere on here that radio reception could be partly from the heated rear window, or maybe there is an aerial pre-amp there, or something like. Might apply to 607, and might ring a bell with someone.
Sounds like a bad shared earth at HRW/other equipment.

[Peter.N.]

Sounds like an aerial problem giving you a weak signal which will make it susceptible to engine/electronic interference.

Peter

[Gibbo2286]

On my C5 the aerial plastic coating had got scratched and let the water in causing the problem, a new aerial fixed it.
I'm not sure if yours is the same set up, mine was a simple matter of unscrewing the old one off and the new one on, a five minute job.

[PC2CV]

I had a look on servicebox mainly because i could not see an aerial on the car. Seems to confirm the theory that the rear window heater is used as part of the aeriel:


Something to take a look at nonetheless and see if there is any corrosion or damage to these parts.

[white exec]

I take it from that parts diagram the radio is using the HRW as an aerial.

This used to be done back in the 70s, and caused problems then (a) if the HRW wasn't properly grounded (although a grounded aerial is an interesting idea!), or (b) if the HRW was switched on. It was also prone to interference from IGN and other sources. The whole idea went out of favour for a while.

The modules above will be aerial signal amplifers, and filters to block out the d.c. and grounding on the HRW. All unnecessary complication i.m.h.o. Is it just FM that this has to handle, or other services too?

Did read somewhere on here that FM came from one antenna, MW/LW from another, and satnav somewhere else?

The radio experts will put me right on all this, hopefully.

[Paul-R]

On my C5 X7 Estate I've had the radio unit changed, the roof aerial and amplifier changed and, recently, the two VHF amplifiers changed. I am still suffering from fluttery Radio 4 reception.

I was told that the aerials for the radio are in the rearmost side windows not the roof aerial. The roof aerial is used for the satnav. I wasn't told where the AM MW/LW part is.