C70 RDAR battery drain step by step
 

Hi all. I recently ran into the dreaded satellite battery drain issue. I dug around through multiple posts on multiple forums to get the 8nfo I needed and thought I’d post a step by step to consolidate the info.

Problem - Battery would drain in 3-5 days if not used.

1. Verify drain. Hook up an ammeter on the 10amp range in line on the negative side of the battery. You will see an initial current of around three amps as systems wake up. This will settle down to about .5 amp. (Which is way too high)

2. Isolate the satellite/ RDAR circuit. On he 2009 C70, pull fuse F16 in the engine bay. Current should drop to zero. (It’s not actually zero but it’s low enough that the 10amp scale doesn’t show it)

3. Reinstall F16, disconnect the meter and in the interior fuse box, pull fuse F64. F64 feeds the RDAR unit and the lock indicators. Econ next the meter to the battery. You will get the initial current of three amps or so. This will drop down to zero after 30 seconds or so.

***IMPORTANT - be sure to disconnect the meter if you open either door. When you open the door, current will jump to about 3-4amps from the dome lights and will drop as they dim and go off. BUT, opening the door apparently wakes up some systems that draw around .6 amp and they do not go back to sleep for 30-40 minuets! This can cause you to chase gremlins that are not there.

4. You have now verified the problem. Now for the fix. You have two choices: get the software upgrade from the dealer. If your car is out of warranty, this reportedly costs upwards of $150. (Side note - there is an class action against Volvo currently in the courts because of this)

The second choice is to disconnect the RDAR unit. In my car, it’s in the trunk, passenger side. You have to loosen the trunk liner to get to it but it’s just a couple clips. No tools needed. The power connector is the lower one at the rear of the unit. Pulling the power will remove the battery drain but now you will have no radio.

The audio system has a fiber optic data loop that will disable the radio if the circuit is not complete. The work around for this is to get a MOST loop. This is essentially a connector that loops the fiber back on itself. You can get one on amazon or eBay. Get the female connector, i paid $14.99 on amazon prime. The data loop is the connector with two orange wires on the rear of the unit. Unplug and then connect the loop.

Double check that the draw is gone and button things up.

Realistically, if you have the MOST loop, you should be able to finish everything in under an hour.

Hope this helps.

I have a 2009 Volvo C70 convertible hard top. My trunk liner is screwed down in several locations with what appears to be T40 screws. Before I go messing around I want to make sure your car with the RDAR unit on the driver side is the same as mine. I wish I had a picture of the location of unit. Is the unit in the floor of the trunk or in a side panel? Is it closer to rear or front of the truck area?

Same here, I have a 2011 Volvo C70, and has had a battery drain problem, replaced the battery once .This is silly, step up to the plate Volvo.

Having reread my original post, I see that I am in fact an idiot. The unit is on the passenger side. I have no idea why I wrote driver side. I’m going to update the post.

Sorry for the confusion.

I bought this loop on Amazon RKX MOST fiber optic optical loop bypass Female adapter for Radio and Audio MERCEDES BMW AUDI PORSCHE https://www.amazon.com/dp/B01FREU5F8/ref=cm_sw_r_taa_hdslBbZRAND9X
for superclass the radio/CD changer to work without the GPS DVD. Wanted that out of my glove box. Hope it solves the battery draining issue too. Thanks

Battery Drain
 

I removed the inoperable GPS DVD and installed the Fiber optics loop. The stereo works, but I think the battery drain is still present. Any more ideas?

This thread is really helpful thank you. I just wondered Mark/AThayer if you had success with this after locating the module. I have had similar issue with battery drain, which could be caused by the same problem. I think I've located the module but it looks more like an amplifier - certainly a google search on the part number points to that. Could I check I am looking at the same thing as you? Power cable, optical cable and a cable loom - green connector - could be audio cables? Disconnecting the unit stops the audio system as mentioned earlier in the thread. I will get a MOST loop - but it just looks like the unit is still required if it is the amplifier I am looking at. Further to this there is another unit in the same place on the other side of the car but there doesn't appear to be any optical cable connected to this unit.

Any comments on your experience would be very much appreciated. I'm UK based so RHD!

Edstoker -that looks pretty much like what I remember. Since I disconnected it and used the MOST loop, I have had no more issues with the battery. The car has been left for as long as nine days and it fired right up.

I'm posting this to hopefully save a lot of time and frustration. (...like me!) :)

- The EXACT location of the RDAR unit on the C70 is just forward of the passenger tail light, mounted on the side of the rear fender, below the antenna.
- To access, pull off the inside cover for the tail light assembly (squeeze cloth together top and bottom), then remove the plastic clips along the top of the side panel. The small, square clips pinch together from top to bottom to pop out. Any other attempt will break the clips (fragile).
- Peel the top of the panel out from underneath the upper weatherstripping and pull back. You'll need to bend the panel a bit but it pops right back into shape.
- Then, look down along the side of the car between the fender and the peeled back liner (I looked over from the side, rather than the back. Easier to see down the gap.) for the 2 orange wires (actually fiber optic cables) that plug into the back of the metal unit. They may be wrapped in crumbling foam.
- Squeeze the small clip on the right/upper side of the connector where it meets the unit and remove.
- Then, place the FEMALE MOST LOOP over the plug on the cable. That will bypass the satellite radio receiver.

As mentioned, hope this helps save some grief, and time.

We had this problem and the dealer did the software fix to disable theXM Radio, which is what the cause of the issue is. They did this on our old one, that was out of warranty. Your mileage may vary.

Another solution is to get XM, which can be had for ~$30 for 6 months, if you get the promotion. Ask them to bill you, then pay by check. In 6 months, call to cancel it, and they may offer the same deal again to keep it.

Thanks so much all for your help in locating the device - really helpful and very much appreciated.

In our case, it turns off the Sat Radio so it doesn't work. If you don't have a subscription, then the issue is it is still constantly looking for a connection to check to see if maybe you did subscribe, even when the car is sitting. This in turn drains the battery. If you decide that you want Sat Radio again, you have have them remove the programming and it will be good to go. This was tested on our old one.

Of note, if you take it in for software updates after having it turned off, make sure that it is still turned off. Our old one had it off, then after the last service, it was back on. Since we were selling it, we left it and just mentioned to the new owner about it.

Furious!!
 

Don't bother with the $150 dealer software upgrade to fix this problem
 

Greetings All,

This is a first time post for me here on the Volvo Forum and probably my last, but I felt compelled to join and revive this somewhat dated thread, in order to share an extremely frustrating and costly experience that we recently had with this whole RDAR issue on a Volvo C70, all in hopes that the information shared here might benefit others. So, I'll try to keep it brief.

OVERVIEW: My mother-in-law passed away in late April, leaving her only child (my wife), a 2011 Volvo C70, and we quickly learned from her mother's surviving friends, that her mother had been plagued in the final months and years of her life, by the battery in this pig, going repeatedly dead on her, without notice or apparent cause. Apparently, week after week it was happening to her, effectively stranding her in various parking lots and other locations, often far away from her home, and forcing her to incur expensive towing charges to the Volvo dealer or other mechanic. Each time, the Volvo dealer told her that nothing was wrong, that they couldn't find anything at all, etc., etc., and yet, each time, if not started almost daily, it would fail on her again, within 2-3 days of sitting idle.

So, we took it into the same Volvo dealer ourselves (after her mother had passed), and we put them on notice that we weren't going to play continued games with them on it any longer, and that we intended to hold them fully accountable on it. Amazingly, they quickly claimed that they had suddenly 'discovered' the source of the problem to be the RDAR device (as if they hadn't known it all along). They confidently claimed the battery and alternator were both perfectly fine, and that the problem would be permanently resolved by an RDAR software upgrade for an additional fee of $150. We reluctantly agreed to pay the $150, and they installed the upgrade, but incredibly, just 3-days of sitting idle afterwards, the newly installed and fully charged battery went dead on us yet again!

So, through additional research here on the Volvo Forum, I learned of the roughly $15 fiber optic bypass cable that others had also recommended as a potential fix; a small loop shaped cable that essentially loops the signal from the RDAR device back into itself. So we quickly purchased that cable and installed it, and we left the power supply cable to the RDAR connected, so that the radio itself would still continue work, but the Sirius XM Radio function was effectively disabled. We then trickle charged the battery back to full charge, and we let the car sit idle for TEN straight days without starting. Significantly, after ten whole days without being started, it started right up for us.

SUMMARY: Our experience in this regard would seem to imply that the $150 dealer-installed RDAR 'software upgrade' was a pointless and unnecessary effort and expense, because the software upgrade alone clearly did NOT solve the problem. Instead, the $15 fiber optic bypass cable was required to solve it. Would that fiber optic bypass cable alone have fixed it, without the software upgrade?? Obviously, that cannot be said with any certainty, but I strongly suspect so! And so, given that suspicion, I would strongly suggest to anyone suffering through this same RDAR-Sirius XM-Dead Battery problem, on any model of Volvo, that you install and test the recommended fiber optic bypass cable FIRST, before paying your dealer $150 for the software upgrade.

I sincerely hope this posting will help save folks some money.

Good luck!

Don't bother with the $150 dealer software upgrade to fix this problem
 

Greetings All,

This is a first time post for me here on the Volvo Forum and probably my last, but I felt compelled to join and revive this somewhat dated thread, in order to share an extremely frustrating and costly experience that we recently had with this whole RDAR issue on a Volvo C70, all in hopes that the information shared here might benefit others. So, I'll try to keep it brief.

OVERVIEW: My mother-in-law passed away in late April, leaving her only child (my wife), a 2011 Volvo C70, and we quickly learned from her mother's surviving friends, that her mother had been plagued in the final months and years of her life, by the battery in this pig, going repeatedly dead on her, without notice or apparent cause. Apparently, week after week it was happening to her, effectively stranding her in various parking lots and other locations, often far away from her home, and forcing her to incur expensive towing charges to the Volvo dealer or other mechanic. Each time, the Volvo dealer told her that nothing was wrong, that they couldn't find anything at all, etc., etc., and yet, each time, if not started almost daily, it would fail on her again, within 2-3 days of sitting idle.

So, we took it into the same Volvo dealer ourselves (after her mother had passed), and we put them on notice that we weren't going to play continued games with them on it any longer, and that we intended to hold them fully accountable on it. Amazingly, they quickly claimed that they had suddenly 'discovered' the source of the problem to be the RDAR device (as if they hadn't known it all along). They confidently claimed the battery and alternator were both perfectly fine, and that the problem would be permanently resolved by an RDAR software upgrade for an additional fee of $150. We reluctantly agreed to pay the $150, and they installed the upgrade, but incredibly, just 3-days of sitting idle afterwards, the newly installed and fully charged battery went dead on us yet again!

So, through additional research here on the Volvo Forum, I learned of the roughly $15 fiber optic bypass cable that others had also recommended as a potential fix; a small loop shaped cable that essentially loops the signal from the RDAR device back into itself. So we quickly purchased that cable and installed it, and we left the power supply cable to the RDAR connected, so that the radio itself would still continue work, but the Sirius XM Radio function was effectively disabled. We then trickle charged the battery back to full charge, and we let the car sit idle for TEN straight days without starting. Significantly, after ten whole days without being started, it started right up for us.

SUMMARY: Our experience in this regard would seem to imply that the $150 dealer-installed RDAR 'software upgrade' was a pointless and unnecessary effort and expense, because the software upgrade alone clearly did NOT solve the problem. Instead, the $15 fiber optic bypass cable was required to solve it. Would that fiber optic bypass cable alone have fixed it, without the software upgrade?? Obviously, that cannot be said with any certainty, but I strongly suspect so! And so, given that suspicion, I would strongly suggest to anyone suffering through this same RDAR-Sirius XM-Dead Battery problem, on any model of Volvo, that you install and test the recommended fiber optic bypass cable FIRST, before paying your dealer $150 for the software upgrade.

I sincerely hope this posting will help save folks some money.

Good luck!

Caution: Install the fiber optic bypass cable first, before paying for the software u
 

Greetings All,

This is a first time post for me here on the Volvo Forum and probably my last, but I felt compelled to join and revive this somewhat dated thread, in order to share an extremely frustrating and costly experience that we recently had with this whole RDAR issue on a Volvo C70, all in hopes that the information shared here might benefit others. So, I'll try to keep it brief.

OVERVIEW: My mother-in-law passed away in late April, leaving her only child (my wife), a 2011 Volvo C70. We quickly learned from her mother's surviving friends, that her mother had been plagued in the final months and years of her life, by the battery in this pig, going repeatedly dead on her, without notice, and without apparent cause. Apparently, week after week it was happening to her, effectively stranding her in various parking lots and other locations, often far away from her home, and forcing her to incur expensive towing charges to the Volvo dealer or other mechanic. Each time, the Volvo dealer told her that nothing was wrong, that they couldn't find anything at all, etc., etc., and yet, each time, if not started almost daily, it would fail on her again, within 2-3 days of sitting idle.

So, we took it into the same Volvo dealer ourselves (after her mother had passed), and we put them on notice that we weren't going to play continued games with them on it any longer, and that we intended to hold them fully accountable on it. Amazingly, they quickly claimed that they had suddenly 'discovered' the source of the problem to be the RDAR device (as if they hadn't known it all along). They confidently claimed the battery and alternator were both perfectly fine, and that the problem would be permanently resolved by an RDAR software upgrade for an additional fee of $150. We reluctantly agreed to pay the $150, and they installed the upgrade, but incredibly, just 3-days of sitting idle afterwards, the newly installed and fully charged battery went dead on us yet again!

So, through additional research here on the Volvo Forum, I learned of the roughly $15 fiber optic bypass cable that others had also recommended as a potential fix; a small loop shaped cable that essentially loops the signal from the RDAR device back into itself. So we quickly purchased that cable and installed it (just under the antenna connection, inside the trunk), and we left the power supply cable to the RDAR connected, so that the radio itself would still continue to work, but the Sirius XM Radio function was effectively disabled. We then trickle charged the battery back to full charge, and we let the car sit idle for TEN straight days without starting. Significantly, after ten whole days without being started, it started right up for us.

SUMMARY: Our experience in this regard would seem to imply that the $150 dealer-installed RDAR 'software upgrade' was a pointless and unnecessary effort and expense, because the software upgrade alone clearly did NOT solve the problem. Instead, the $15 fiber optic bypass cable was required to solve it. Would that fiber optic bypass cable alone have fixed it, without the software upgrade?? Obviously, that cannot be said with any certainty, but I strongly suspect so! And so, given that suspicion, I would strongly suggest to anyone suffering through this same RDAR-SiriusXM-Dead Battery problem, on any model of Volvo, that you install and test the recommended fiber optic bypass cable FIRST, before paying your dealer $150 for the software upgrade.

I sincerely hope this posting will help save folks some money.

Good luck

Thanks so much for posting! I'm pretty sure the Sirius radio is my problem but I'll check to make sure. The dealership tells me my battery is weak because of the cold weather and short trips but I don't buy it. Gonna try this and bet it fixes it. Thanks again.

The loop is the answer
 

The unit is located in the trunk on the same side as the antenna (shortest distance from unit to antenna)

How Do I Access the RDAR Unit?
 

UPDATE: I posted this question and then saw 4HisGlory’s post in this thread with exact instructions as to where to access the RDAR unit. I’m always better with video tutorials (!) but I fingers crossed we can now get the job done!

I have been having the same problem with my 2009 C70. Last week (before I read your post) I had the Volvo dealership update the Sirius software which was ‘sort of/kind of’ going to fix it. They told me if that didn’t work—it didn’t, after spending $250—I would have to buy a new computer module that controls the audio system(s). So, this week when I stumbled across your post, I was thrilled and immediately bought the MOST loop you described.

My husband and I just tried to follow your directions but we can’t locate where the RDAR unit is. I hadn’t noticed before but there is a metal ‘bracket’ and cover in the trunk (it looks like some type of after-market ‘add-on?) that is preventing us from pulling back any liners that are clipped on [see attached photos] except for along the side which didn’t reveal anything that looked like the power unit.

Are we looking in the right place? Or does anyone reading this know of a video which shows how to get to the RDAR unit (more specifically, the power unit). Finally, is the metal bracket (with the cover) detachable?

Thanks for any help/advice you can offer.
NB: I taped up the cover temporarily so I could get it out of the way!

https://cimg2.ibsrv.net/gimg/volvofo...f6b869d73.jpeg
https://cimg5.ibsrv.net/gimg/volvofo...7ad16c637.jpeg
https://cimg6.ibsrv.net/gimg/volvofo...5d8571713.jpeg