2001 V70 non-turbo Electrical Gremlin - trashing batteries

[worldbound4now]

I started this topic in another section, but my saga has evolved into something that needs to migrate into the V70 arena. If you don't want to read the whole story, skip to the last paragraph for the root question and please provide me with your thoughts and experiences. Thank you!

Car: 2001 V70 with approx 153000 miles

Issues:

SRS light has been on for months. Car has run great.

4/24/2010 - Wife is driving the car to work and receives the "El. system" needs service message with the battery light on. I met her after work and we drove together to an Autozone which was about 5-8 miles away. On that journey, the V70 gained mistook the spring season as our end of December holiday and started setting off lights. First, the chronic SRS message and El. system message. Next I noticed my yellow triangle turn red and saw a brake system failure warning message with the ABS light on the instrument panel activated. Within a few seconds I noticed the pull over safely message and at this time was probably within a mile of the auto parts store. As I looked down, I now noticed all messages gone, the spedometer stuck at "0", my turn signals don't work, and my climate control system has been disabled. The car started to run a little odd.... as if in "W" mode when taking off from a stoplight. Thankfully I was pulling into Autozone within a minute or two more and safely parked the car.

I limp into auto zone and they hook up their tester on the non-running car. With a 2.5 amp draw, the voltage drops to 8.5 volts almost immediately. Within a short few minutes, their machine beams out the message "bad battery". Luckily, they had a replacement battery on hand. Out with the old, in with the new, car starts up and runs great. The only residual lights on the warning light cluster is the red battery, and the message center notes the car needs El. system service as well as the chronic SRS light. With a knowledge deficit, I felt this was maybe an error code that only the dealer could clear. I make one short (2.5 miles round trip) to the store later that night and let the car sit until Monday.

On Monday, I go out to the car to head to the gym and low and behold, all my error codes and lights are off. Painfully so, I realized that everything was off. Key in the ignition and not a blip of power. No dome light, no dash response, nada, zilch. (insert many profane words that I barked out as I began pulling out tools/testers). Dead. Battery posts are spotless. Battery ground is firm to the battery and to the interior of the car. Positive lead on battery is connected firmly.

When my wife got home, I headed to the auto parts store where I purchased a cheapie 1.5 amp battery charger and a digital multimeter ($50 total... cheaper than an hour at the local shop). Initial multimeter voltage across battery posts was not reading. I hooked up jumper cables from my running car and, after a few minutes pause, the V70 fired right up. Voltage at idle 13.1. Voltage at 2,000rpm was 13.8. Sounds like I may have purchased a dead battery. I put it on the weenie trickle charger for an overnight proverbial electrical soaking.

4/27/2010 I head out this morning greeted with the "abort" light flashing on my charger. Key in the keyhole results in silence and darkness. )(*^(*&%$!! I pulled the battery and headed back to Autozone where they replace my battery after testing failed. No cost, easy warranty swap.

My optimism is rising. Maybe that Duralast battery was crap. Maybe? Out of fear of two strikes in a row, I have the Autozone rep connect the brand new replacement battery to their tester. It passes their testing sequence. Phew.

I get back home and install the new battery. Battery disconnected shows 12.8 volts. Yippee... Battery installed, dome lights come. YES!!!

Key in the keyhole and advanced forward.... SUHWEEEET.... the dash lights up like always. Hit the starter and she fires right up. But wait... a new message and odd behaviors. Now the El. voltage "high" message is showing, a brake system failure light is on, and the car is cycling through high draw devices. I hear the engine fan cycling on and off, the climate control fan cycling on and off, and see the rear window defrost indicator flashing at me on and of.

A quick run back to the battery reveals voltage variables from 13.7-18.6 volts as these devices cycle on and off. HOLY CARP. The charging system is really ramped up. I run forward to turn the car off. Checked battery voltage with car off... 12.6 volts. Disconnect the ground, let the car sit for 11 minutes (I watched the clock and drank a beer), and reconnected the ground.

Same issue. My voltage is too high, and my car thinks it's Christmas again.

Now, I've wrenched a lot as a child and realize that most alternators have/had a regulator built on or inside of them which does as it's namesake states... regulates the charge. On the 2001 V70, is the voltage output from the alternator controlled by the alternator and monitored by a central electronic module of some sorts, or is there a central brain that actually controls the alternator output? I'm tempted to head out and purchase a re-manufactured alternator, but don't want to throw my money away just to find out that this car regulates its charging system from a higher level computer somewhere outside of the alternator assembly.

Thank you for any advice or information you may have to aid me shaking down this electrical problem!

worldbound4now

[jblackburn]

Your voltage regulator is toast.

It's an integral part of the alternator, as you suspected. Some newer models use an alternator with a clutch assembly that cuts it out to save gas mileage/give more power. I don't know whether yours has this or not, but you DONT need that if you're going to replace it.

You may be able to find just the brush/voltage regulator assembly and pop it into your existing alternator housing for much cheaper. Such assemblies exist for the older 850/-70 series alternators, though I'm not sure about the new ones.

For the meantime, don't drive it, you risk damaging electrical systems and/or exploding your battery putting that kind of voltage through them.

[worldbound4now]

I pretty much figured the gray rock was parked until I could resolve this issue. I found Bosch regulator W0133-1831812 and think I'm going to head that route. I want to repair things correctly, but don't want to sink too much money into this old, high mileage car.

Any other opinions related to this topic?

[worldbound4now]

Thank you for the advice. This was by far one of the easier jobs that I've done on my V70. I pulled the alternator, removed the black plastic cover on the rear of the alternator, removed the old regulator and then reassembled with the new. The most difficult part of the entire job was getting the serpentine belt back on in the correct order.

Just a side note, the original, bad regulator that I removed from the car was Bosch #F00M145229 and it was replaced by Bosch #F00M145369. It was an easy, direct fit replacement and I now have consistent charging voltage high 13's when at idle with minimal load (exterior lights on only) to high 12's with A/C on full, heated seats on high, radio on, flashers flashing, and high beams on headlights.

All of my warning lights are off except for my chronic friendly SRS light and I also blew out my dim level headlight bulbs when I was having the high voltage error, so that message is also present.

I'm no longer helpless.

worldbound4now

edit: BTW, the regulator was just under $60, so this was not only a relatively easy repair, it was also cheap!