Random stalling, no electrical

bobsnow100 · Post by **bobsnow100** » 23 Jul 2012, 08:37

Hello All
I have a 2001 xc70, 225,000 miles
Car will randomly die while driving, It can happen anytime without warning. The car will run perfect for a month or two or even longer but then just die out anytime. When it does, you try to restart it and nothing. No electrical .No starter sound, no horn,no lights. You can hear a small buzz sound when you turn the ignition though but that is it. Had to be towed twice in the last month.
After car sits in the drive a few hours, you go to try to start it and it starts like nothing was ever wrong. Drive it for days and weeks and then it will happen again. I've had the battery, alternator and starter all tested and they are fine
I've checked battery and ground connections.
No sure if there is a main relay or something of that nature or if others have experienced something like this with a solution.
Would it have anything to do with the security system? Ignition Imoobilizer?
This is very dangerous when my wife was driving and it did it on an interstate highway at rush hour.

Post by **jimmy57** » 23 Jul 2012, 14:02

Has anyone scanned it for full system codes?
I have had cars with faulty alternators that would quit charging with no warning light and the car would die and then after it sat battery would restore enough with no charging or being jumped, start and charge again. These cars always have weakening headlights and slowing blower motors and your car should have had warning messages. A good battery will recover a bit from going dead and re-start a car. I have had bad alternator cars that wouldn't start and get towed and the next morning battery would crank it over with no jump. I would think this would have gotten more regular or would have reached total no charge after this happened a very few times.

bobsnow100 · Post by **bobsnow100** » 24 Jul 2012, 09:05

Thanks for the response
When AAA towed it, they did a scan check and everything on the printout said the alternator was fine, battery fine, starter fine and the alternator was putting out the right volts..
When the car runs , the lights are super bright, no dimming, no indication that the battery is going dead. Car just instantly dies.
I wonder if the alternator is going bad and sometimes registers ok except I've never experienced the effects of a bad alternator on this car like dimming lights, faint horn not sounding loud ,etc. If the diode is bad in the alternator then maybe it is grounding out the system ?? but then why would the car run fine for 2 months or whatever before the same problem happens again.
Never had a full scan by Volvo.
I do have my own code reader but I know it isn't a complete as a full scan could be. Looks like I might take it to volvo for that.
Thanks

Post by **igel513** » 24 Jul 2012, 15:43

bobsnow, how about checking all battery connections. Clean and check for tightness and corrosion. Hopefully it's just some loose contact that's causing it to stall and loose elec.. Also clean the ground wire from the engine to the body. Hope it helps. Good luck.

bobsnow100 · Post by **bobsnow100** » 25 Jul 2012, 10:03

Thanks,
That was the first thing I did. The battery is in the trunk and the connections look like new. Battery is fairly new and tested fine,
All the connections and terminals are clean and tight.
I was thinking of disconnecting the battery and removing the ecm and spray electrical contact cleaner on all the contacts and see if that helps.

Renie21 · Post by **Renie21** » 14 Aug 2012, 09:10

Please describe what happens when it stalls while driving. This is important. I have both problems with my 2004 XC70. Appears to be the CEM, water has leaked in and causes corrosion. PLEASE report to NHTSA. Too many Volvo owners are having this problem and not enough report. The stalling while driving is serious and dangerous.

bobsnow100 · Post by **bobsnow100** » 14 Aug 2012, 14:19

It just dies and coasts to a stop ,then when you try to start it, it does nothing , almost like the battery is disconnected. No noises except a faint humm sound like when you put the key in the ignition with the doors closed. I've had to get towed home and then later on, maybe a hour or so, you go to start it and it starts like nothing was ever wrong. You might drive it for weeks and then it may happen out of the clear blue.
I did just change the alternator last week because just 2 weeks ago my battery was drained while at the beach for 3 hours. Jump started it and drove one hour and then the next morning it was drained again.( the battery has been tested and is good)
I was reading something about the ECM not telling the alternator to charge the battery.
When then electrical problem happens, it triggered my srs light to come on.
It is very nerve racking

Post by **chrism** » 15 Aug 2012, 10:30

I think I would second Renie21's suggestion. Check into the CEM for possible corrosion caused by water intrusion. Apparently it's a lot bigger issue than Volvo has been willing to cop to. It's funny though that they did redesign the wire harness grommet around 2005, at least on the XC90's.