2005 S60 T5 HU650 radio FM intermittent

[napmayer]

I have acquired a 2005 Volvo S60 T5 SE some time ago. Despite being very happy with the car the head unit HU650 started intermittend audio on FM selection. I have replaced the head unit from a salvaged car but experencing the same problem. AM and CD works fine so the problem is not with power to the unit or speakers. The radio pre selects fine and pick up the stations but no audio. Comes back after a while and then goes again. I found others with the same problem but no solution offered. Anyone with advice please help

[Sunapeelakers]

I have acquired a 2005 Volvo S60 T5 SE some time ago. Despite being very happy with the car the head unit HU650 started intermittend audio on FM selection. I have replaced the head unit from a salvaged car but experencing the same problem. AM and CD works fine so the problem is not with power to the unit or speakers. The radio pre selects fine and pick up the stations but no audio. Comes back after a while and then goes again. I found others with the same problem but no solution offered. Anyone with advice please help

Mine is doing this same thing, any closure to this?

[oragex]

The problem is usually the antenna

Aerial
The audio module (AUM) has an aerial system for AM and FM. This consists partly of an AM aerial and partly of a dual aerial system for FM (Diversity reception). The dual aerial system is used to reduce Multipath interference. One aerial is integrated in the rear windscreen (left-hand rear side window V70/V70XC). The other aerial is integrated in the rear bumper. The signals from the aerials are amplified or adjusted by each individual aerial amplifier.

MAIN
Radio aerial. Integrated in the rear windscreen on the S60/S80
Aerial amplifier FM/AM, located in the D-post

SUB:
Aerial amplifier for the bumper aerial
FM aerial integrated in the bumper

[Sunapeelakers]

The problem is usually the antenna

Aerial
The audio module (AUM) has an aerial system for AM and FM. This consists partly of an AM aerial and partly of a dual aerial system for FM (Diversity reception). The dual aerial system is used to reduce Multipath interference. One aerial is integrated in the rear windscreen (left-hand rear side window V70/V70XC). The other aerial is integrated in the rear bumper. The signals from the aerials are amplified or adjusted by each individual aerial amplifier.

MAIN
Radio aerial. Integrated in the rear windscreen on the S60/S80
Aerial amplifier FM/AM, located in the D-post

SUB:
Aerial amplifier for the bumper aerial
FM aerial integrated in the bumper

I could understand it being an antenna if I was just getting static... but when it cuts out there is no sound at all. No static, no whines, nothing. Itll work fine with perfect reception for a minute, then cut out with 0 sound for a minute at complete random.

I'll also mention that the outside temperature showing on my dashboard is all over the place and mostly completely way off. For instance, if it's 10f outside (northeast US), that will show anywhere from -30f to 10f. Are these two issues related?

[Sunapeelakers]

The problem is usually the antenna

Aerial
The audio module (AUM) has an aerial system for AM and FM. This consists partly of an AM aerial and partly of a dual aerial system for FM (Diversity reception). The dual aerial system is used to reduce Multipath interference. One aerial is integrated in the rear windscreen (left-hand rear side window V70/V70XC). The other aerial is integrated in the rear bumper. The signals from the aerials are amplified or adjusted by each individual aerial amplifier.

MAIN
Radio aerial. Integrated in the rear windscreen on the S60/S80
Aerial amplifier FM/AM, located in the D-post

SUB:
Aerial amplifier for the bumper aerial
FM aerial integrated in the bumper

What’s considered the d-pillar on the sedan?

[oragex]

Perhaps that line was the for V70 model. I understand the S60 has wires near the rear windshield, so perhaps the antenna connectors would be located inside the C-pillar ?

[Sunapeelakers]

Perhaps that line was the for V70 model. I understand the S60 has wires near the rear windshield, so perhaps the antenna connectors would be located inside the C-pillar ?

I have tried a CD and I get the same intermittent no audio - would this still indicate the antenna amplifier is junk or something else?

[EngineeringBloke]

napmayer,
most FM radios are able to mute the audio output if there is no strong signal. As you switched radios (HUs) and had the same symptom, this points to the antenna or antenna amplifier.

There has been an issue with the antenna amplifier that is fixed with a short length of brass strip. The strip is inserted in either the input or output of the antenna amplifier. There is a service note about this.

Further, the antenna amplifier is powered by 10 volts output from the HU. This is a Ford idea. If the amp gets 12 volts from an after-market HU it does not work well! In your case, there may be temporary loss of power due to a poor connection.

Sunapeelakers,
your issue is different as it is not just the FM input. As CD is also affected, you have a different cause. Do you have an extenal amp under the passenger seat - perhaps a poor connection via the DIN (6 pin) input connection, or power to it?