RNS-E head unit no power

[ciaranc]

I have a RNS-E (with satnav) headunit in my A6 C5 avant. The car was parked for 2 weeks while on holiday and the battery went flat. Removed the battery and replaced with a new battery but since the battery replacement my RNS-E head unit has not worked. The amp in the boot also gets no power.
I checked and replaced the 5Amp fuse at the back of the head unit.
I checked and replaced the radio fuse on the fuse panel
1.9 tdi A6 C5 Avant FE

I check the output of the radio fuse behind the fuse panel, its working.
I checked for 12volts on pin D12 of the RNS-e but no power there at all.
I checked the power at the amp, no power delivered there either.

so couple of questions
1. does the power feed go to the amp first and then the head unit or the head unit to the amp direction?
2. is there another fuse hidden someplace i cannot find?
3. has anyone else had a similar issue that they were able to resolve?

thank you for any help which is greatly appreciated.

 

[Scottnb]

I have a RNS-E (with satnav) headunit in my A6 C5 avant. The car was parked for 2 weeks while on holiday and the battery went flat. Removed the battery and replaced with a new battery but since the battery replacement my RNS-E head unit has not worked. The amp in the boot also gets no power.
I checked and replaced the 5Amp fuse at the back of the head unit.
I checked and replaced the radio fuse on the fuse panel
1.9 tdi A6 C5 Avant FE

I check the output of the radio fuse behind the fuse panel, its working.
I checked for 12volts on pin D12 of the RNS-e but no power there at all.
I checked the power at the amp, no power delivered there either.

so couple of questions
1. does the power feed go to the amp first and then the head unit or the head unit to the amp direction?
2. is there another fuse hidden someplace i cannot find?
3. has anyone else had a similar issue that they were able to resolve?

thank you for any help which is greatly appreciated.

Hi,

I have the same issue with the RNS-E unit on my newly purchased 2005 Audi Allroad.

I bought it recently with no radio working. Seller said it was working until he left it for a few weeks and the battery went flat.
Since then ,it hasn't worked.

Fuses seem ok but it doesn't turn on.

Did you fix your problem?

Cheers,
Scott.

 

[ciaranc]

Hi,

I have the same issue with the RNS-E unit on my newly purchased 2005 Audi Allroad.

I bought it recently with no radio working. Seller said it was working until he left it for a few weeks and the battery went flat.
Since then ,it hasn't worked.

Fuses seem ok but it doesn't turn on.

Did you fix your problem?

Cheers,
Scott.

Hi Scott,

have you checked the fuse on the back of the unit ? If the seller started the car by jump starting it then it may have send a power surge to you head unit.

i have narrowed my issue down to a broken power wire in the loom between the head unit and the fuse block, as the radio etc. works when i supply power directly to the power input at the back of the unit. i will add some pictures when i get around to replacing it.

perhaps this wiring diagram might help you in finding your problem

 

[Scottnb]

Hi.
Thanks for the reply. Yes, both the main fuse in the side of the dashboard and the small fuse behind the head unit are ok.
I'll get the multimeter out and check for power at the connector
Cheers
Scott

 

[cheppndepp]

Hi Scott,

have you checked the fuse on the back of the unit ? If the seller started the car by jump starting it then it may have send a power surge to you head unit.

i have narrowed my issue down to a broken power wire in the loom between the head unit and the fuse block, as the radio etc. works when i supply power directly to the power input at the back of the unit. i will add some pictures when i get around to replacing it.

perhaps this wiring diagram might help you in finding your problem

Hi Ciaranc

Did you come to a successful conclusion with resolving the power issue with the head unit?
I've just picked up a 2005 allroad with this exact head unit and problem! doesn't want to power on. I have replaced the small fuse in the back of the head unit so far but no success.

Any info would be much appreciated!

Cheers

 

[Scottnb]

Hi Ciaranc

Did you come to a successful conclusion with resolving the power issue with the head unit?
I've just picked up a 2005 allroad with this exact head unit and problem! doesn't want to power on. I have replaced the small fuse in the back of the head unit so far but no success.

Any info would be much appreciated!

Cheers

Hi,
I found the problem with mine. I think it's a common issue. Underneath the carpet, under the passenger seat, there is a wiring harness. There are several red wires that terminate in a copper terminal that is covered in a rubber boot.
The copper on my car had turned into green power. Completely corroded to nothing. I imagine it's something to do with water ingress that may accelerate the copper corrosion?
There another post on here somewhere that describes it.
I trimmed the ends of the 5 wires and eventually, soldered them together and covered them in insulation tape.
My radio now works !
I did had to cut the carpet under the seat to access the wires , I couldn't see another a to access them.
Hope this helps.
Scott.

 

[Scottnb]

Link to post:-

Fuse 37 OK - No Power at Radio or Amp - AudiWorld Forums

A6 / S6 (C5 Platform) Discussion - Fuse 37 OK - No Power at Radio or Amp - Hello All, The Bose symphony radio on my 2003 A6 Quattro went out a few months ago and I finally got around to pulling it out this week. The red/yellow wire that is supposed to come from fuse 37 has no power but fuse 37...

www.audiworld.com

 

[cheppndepp]

Wow that is definitely some corrosion that has happened over a long period! I wonder where the moisture has come in for that to happen?

Thanks for the swift reply, I'll read that other thread and take a look later today.
Cheers!