Have this 2006 C70 with about 65k miles. Saturday found the car with a completely dead battery. Not a huge surprise, original batteries fail like this often enough.

Put in a new battery, seemed okay. But Sunday drove the car a few miles and started getting weird error messages (power steering, traction, etc). Opened the hood and had a strong smell of burning electrical. Car was running and the battery voltages was only 7.5V. Finally triggered an "urgent charging system" error message.

I pulled the battery cable and let it cool down, I figure the alternator is about the only thing that would pull enough current to drain the battery without blowing a fuse.

Started to take parts off to get at the alt, but can't even get the air box out of the way. Is there a how-to for this model somewhere? I searched but did not find anything. I've done the alt on an 850, but this C70 is a much tighter bay.

Also, I keep seeing references to replacing the regulator alone. Where is that available? I'm wondering if this car might just need a whole new alternator anyway, in case it has a shorted winding or something like that.

Thanks for any advice,
-Michael

 

You most likely wont be able to get the voltage regulator alone from anywhere like advance or autozone, but maybe the dealer. I kind of doubt a short in the winding though. It also might be worn brushes, although that also seems unlikely with how many miles are on the vehicle.

 

The CEM controls the alternator via LIN communication.

 

Ended up getting a new alternator from the dealer... still pending installation on this one. I'm thinking either shorted regulator or diodes, something had a very strong smell of burning electrical under the hood. I don't think anything else would do that, drain the battery, and not burn out a fuse.

Is there a belt routing diagram somewhere? I've been searching all morning and only found ones for the old T5 engine.

 

There should be a sticker under the hood that shows the belt routing.

 

Volvo hasn't used belt routing stickers in years.

The inner belt goes around the compressor, tensioner and alternator. The outer belt goes around the crankshaft, compressor and tensioner. I don't have a diagram, sorry.

 

Thank you!

So there's no hydraulic power steering pump? What does it have, an electric pump for the hydraulic fluid?

I'm wondering now if that is an issue on this car, because the message center was giving steering error messages along with the charging system). I never did pinpoint the exact location of the burning smell, other than the side or rear of the engine. that wouldn't have been accurate anyway since the radiator fan was running. And, even if the steering was faulty, if it pulled enough current to drain the battery then it would certainly blow the fuse.

 

Yes, an electronic pump under the passenger headlight.

Low system voltage due to a bad alternator can cause the steering to set warning messages and malfunction.

 

Thanks! I didn't know it was up front. The burning smell I thought was coming from the side/rear of the engine bay, so nevermind that. The system voltage was down to 7.5V so no doubt all of the computer modules were going nuts.

I'm fairly confident the alt is the problem on this one... will check out no-run current draw from the battery before spending all the time on a new alternator, but I'm fairly sure that will be the culprit.

 

Yeah, I would agree. The alternator is most likely your problem.

 

I replaced an alternator on a Mini. About 15 seconds into the run the new starter burnt up. Had to get another one.

 

It was indeed... the old alternator had a dead short between B+ and ground. Looked very crispy inside as well.

New alternator from Volvo... $690 *yikes*. Was not that bad to change, once we took off the passenger side wheel and liner. Had the new battery on the charger, seems to have recovered okay. The new alt is charging it at 14.0 vdc and everything seems to be fine!

Thanks again for everyone's help. Hopefully this is the last alternator this car will need.

-Michael

 

Does anyone has a video or step by step for 2002 volvo c70 replacement? Thankyou

 

Is the 2002 like the 2006? Or is it the older engine?

Nevermind, just looked one up on eBay, that has the old Volvo engine. Did the same job on a '94 850. It's straightforward--remove the hoses in the way, including the upper coolant hose. Unbolt the power steering pump to get it out of the way (leave the lines connected), and remove the alternator. Not much tricky, just a lot of little things need to be moved before it comes out.

 

Hi MHamilton

appreciate your response and have accomplished the job..yes a tight fit and those two extra compressor screws had to be loosened..otherwise doable and yet so much more complicated than the old days..again my thanks..