ALternator, regulator, or battery

proinfo57 · Post by **proinfo57** » 03 Jul 2010, 09:54

Volvo v70xc, (2000). after driving for 20 minutes or so at 55/50MPH, at an intersection the speedometer stopped working and about 60 seconds later SRS light came on then a few more dash lights. Stopped the car and it would not start back up. No known issues prior to this event. Towed the car and battery was too low to roll windows up. Tow truck jumped the battery in order to roll windows up. Tried cranking the car and it cranked fine. As soon as the jumper cables were removed the car started powering down until it stopped running. My thoughts are the alternator. The car had no signs of battery fatigue etc. Prior to the event the car was driven for 3o minutes, turned off for 30 minutes, cranked perfectly and driven for another 20 minutes or so before the failure.
Any thoughts would be appreciated. Of course this all went down as I started traveling for the holiday, wife, and 2 dogs in the car!

bv_s80 · Post by **bv_s80** » 03 Jul 2010, 12:11

This definitely sounds like the voltage regulator. Unfortunately, most chain parts stores don't sell just the regulator as it is an internal component of the alternator (with the brushes attached). If you can find an alternator/starter shop in the area, they can get you the voltage regulator and may even have it in stock (50 or so)...On the other hand you can get complete alternator from chain parts stores such as Oreilly and it will carry a lifetime warranty (250 or so)..note you may have to use your old pulley if you go for complete unit.

Hope this helps
-bv

proinfo57 · Post by **proinfo57** » 03 Jul 2010, 13:20

Thank you for the reply. I am getting the battery charged at the moment in order to verify if the battery is good shape. This battery is less than a year old. I am not comfortable attempting to place fully charged battery in the car and hope that I could make it to an Auto Zone type store in order to test the electrical. The car is at a local repair shop now, but they are closed for the July 4th holiday. I will post my findings.

Thanks again,
Tom

proinfo57 · Post by **proinfo57** » 03 Jul 2010, 15:26

Latest scoop. Charged the battery for several hours, advanced Auto checked the battery and the battery checks "good". I placed the battery back in the car and the car cranks fine, no dash light issues at all. I was concerned about driving a short distance, but did so and all went well. The car seems as if nothing happened. Could removing the battery for a period of time reset the computer system in some way?

Tom

bv_s80 · Post by **bv_s80** » 03 Jul 2010, 15:47

If going to advance is a "short" drive, then I suggest you take the car and ask them to test the alternator (and battery again).

They should be able to run a simple test to verify the voltage output of the alternator. A short distance drive does not sound the same as your previous trip started out...it could be that the ac and other accessories hasn't had time to drain the battery down yet (if the alternator is not able to keep up). My guess is that they say low voltage output or something similar, which would confirm it's the voltage regulator.

-bv

Post by **Pauloil** » 03 Jul 2010, 17:02

or cables
search voltage drop and B cable
your prob could be bad B cable: batt to fuse box, famous for making wierd things happen
to do voltage drop test on this and your starter cable(batt to starter): run car at 2K rpm with fan on high and rear window defogger on. normal drop is less than 0.2V what you are doing is asking how much voltage is not able to go thru the cable

proinfo57 · Post by **proinfo57** » 23 Jul 2010, 08:16

Update on the repair. I had the alternator checked and it was bad. I choose to go to an Alternator / generator repair shop. They tested and replaced with a new alternator. Very honest shop. $165 for a rebuilt, $85.00 for the install.

The car performs much better than it has in the past. Of course the car is cranking and running properly. It appears to have more get-up and go. Recent road trip offered 26.4 MPG, (1000 mile trip). I also had an issue where the AC compressor would turn off and cool air would not longer circulate even though the fan was blowing properly. The AC would run for 5-10 intervals fine the compressor would stop. Turning AC off for a few minutes would allow get it cooling again for a few minutes. After the alternator repair the AC works perfect. I can run it on full blast in stop and go traffic without any issues. My assumption is the old alternator was not working properly and system power down the compressor when voltage was low.

Post by **cn90** » 23 Jul 2010, 12:12

Just curious for those who have failed alternator, at what mileage did your alternator fail?

125K?
150K?
175K?
200K?

proinfo57 · Post by **proinfo57** » 27 Jul 2010, 12:10

Post by **jblackburn** » 27 Jul 2010, 12:39

Mine has been in the process of dying for about a year now (first noticed ~150; still going at 176). It only charges ~13V, and the dash lights fluctuate a little bit at idle in the wintertime, but I'm waiting on it to finish dying before I dig in to replace it. I just don't have the money to throw at things it doesn't yet need