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Discussion Starter · #1 ·
Hello,

Same old battery drain problem with my RNS-E in my B5 S4. Anyway, I took some readings and the unit is pulling 2.5 amps from my battery when everything is off. I pulled the unit and removed Connector I (from the orig. Symphony I unit) from the harness. I took another reading and it showed 1.8 amps. I still have not solved this problem and would appreciate any thoughts. Should I check some other pins with my multimeter while the unit is connected?

Thanks
 

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Discussion Starter · #2 ·
Tried it again after 5 minutes

Ok,

I tried it again after the unit was completely off for 5 minutes. Now the battery drain is 0.02 amps with connector I (from Symph I) disconnected from rns-e harness.......and 2.5 amps with it still connected to rns-e harness.

any thoughts?
 

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Yeah, sounds like you have the same old "constant amp power" problem that many people have. Make sure the wire that powers your amp on (20-pin connector, pin 6) goes to pin D13 on your RNS-E... NOT pin D16.
 

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Discussion Starter · #4 ·
Thanks NSXjr but the pins are correct, i tried this though

I turned the unit on and placed the multimeter on pin D13. It showed 9.2 volts. I then turned the unit off and after a minute or so the reading snapped to 0 volts. So doesn't this mean the amp is not being powered after the unit turns off for a minute. If I am right then the 2.5 amp draw is coming from somewhere else?


Thanks
 

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That is your BOSE ground wire. It is fine.

The behavior you measured on pin D13 is correct. Now you just need to make sure that your amp power wire actually connects there instead of D16 which is a constant power source... just like B4.
 

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Discussion Starter · #7 ·
OK, I located the bose amp in the back of my vehicle and unplugged all the cables that go to it. Went back to the battery to measure and there is STILL a 2.5 amp drain. What the heck is going on here. Does this mean the HU (RNS-E) is pulling the 2.5 amps? It must, although I am clearly no expert. Again, the 2.5 amp drain STOPS when I disconnect connector I (from Symph I) from my RNS-E harness. Man......does someone want to buy my S4 before I rip it apart :x
 

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If it stops when you pull connector I then it could be:

-amp (you just ruled this one out)
-CD changer/phatbox/ipod
-ignition swtich signal over CANbus

How did you supply CANbus from the cluster to the headunit? If it does not pass through connector I then you can rule out the last item which just leaves your cd changer.
 

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Discussion Starter · #11 ·
Well I removed that plug in the trunk that connects the CD changer and still the 2.5 amp drain. So now I've ruled out the CD changer and the amp, since both are disconnected and still the 2.5 amp drain. When I pull the radio fuse (37 I think) or connector I (from Symph I) the battery drain goes away as I said before. I guess this narrows the problem down to the RNS-E itself. Any more suggestions would be great. I'm pretty sure CAN is working fine as the unit:

powers on when I insert the key
powers off when I remove the key

arghh. I sure would like to put this thing back together and start driving it again :cry:
 

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Discussion Starter · #13 ·
thanks but it's definitely the 20 pin connector.. Last night I went over all my conections for a second time from RNS-E to Symphony connectors. Everything was correct. Maybe it could be CAN? Should I measure those pins? Don't know what I could do about it if it was CAN. I forgot to mention that I installed this unit at the begining of last summer, basically went the entire summer and fall without a problem (never had a dead battery). It's like something magically changed for the worse.
 

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Yes, but how do you know that this 2.5 amps is the cause of your bad battery? Did you test all the other circuits and the charging system?

It is possible that the RNS-E is supposed to be pulling the 2.5 amps and you are assumiing this is causing your battery problem because of its bad reputation.
 

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Discussion Starter · #17 ·
You are exactly right. I am assuming everyone else with an RNS-E doesn't have a 2.5 amp drain on their battery when the car is off. I have read that the typical drain on a car battery when it's off is .075 volts (from clocks, security alarms, radio presets, etc.). Maybe I should check that. Are you saying everyone with an RNS-E might have the same amp drain?

Thanks again
 

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Sure, it is possible but I have never checked mine. Just as a troubleshooting step it makes sense because you say your RNS-E worked well with your battery for a few months, but then you suddenly had a problem. This could mean two things. Either it took 2 months for your RNS-E to finally kill your battery, or something else has gone wrong and is causing the problem.
 

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Do you have a Bluetooth module?
 
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