98 V70 Voltage Regulator

Post by **rmmagow** » 02 Oct 2012, 09:23

Is the voltage regulator part of the alternator? Is it replaceable by itself or should I just put in a new alternator? Symptoms, flickering dash lights, flickering "service engine soon" light and flickering CEL when it is on. Don't know if the headlights are doing anything strange. Radio does not make any unusual noise when the lights flicker. Worse in the morning.
I need to replace the bulbs in the dash and will be doing the dashpad remove later this week. Any grounds/connections I should check while I'm in there? Can a beginning to fail B+ (to the fuse block) cause the flickering or would that cause a lot more problems? Car's running OK, 180K, no starting issues. Trying to stay ahead of dead car type failures.

ONV70XC · Post by **ONV70XC** » 02 Oct 2012, 09:37

Do you also see battery light?

Post by **BEJinFbk** » 02 Oct 2012, 09:53

Put a meter on the main post of the alternator and see if the voltage is stable there.
If it is, start looking at cabling and connections. If it isn't, get a new regulator.

Post by **misha** » 02 Oct 2012, 17:44

Voltage regulator is replaceable.Before you blaim alternator or voltage regulator,perform a voltage drop test:

alternator and regulator.pdf: (130.92 KiB) Downloaded 959 times

Note that healthy charging system MUST have 13.5-14.4v across battery terminals with headlights,heater blower ON,at idle.If it's below 13.5v at idle with headlights,blower ON that's not enough to properly recharge the battery.

Post by **cn90** » 03 Oct 2012, 10:04

1+,

I will tell you my secret re checking voltage.
Of course I have the multimeter, the problem is: you have to get out of the car, open the hood, then check the voltage.

I will tell a little trick: recently, a new product comes out: "cigarette voltage checker".

I have this "cigarette voltage checker" in the glove box just for a quick check (this way you don't have to open the hood or trunk to check the battery). I have verified this against the real multimeter and I have to tell you this little gadget is very accurate.

Kind of a "lazy" way to check the battery from the cockpit LOL.

Example is below for something that costs $14, but again, you can find something similar for $6-$8 on ebay:

: VoltageTester.JPG (73.55 KiB) Viewed 5338 times

Post by **rmmagow** » 03 Oct 2012, 12:12

I'll pick up the Equus thing tonight, walmart has it for 17. Only battery light I ever had was about 3 months ago when I mis-judged the depth of a puddle and the serp belt started slipping pretty badly. Once it dried (30 seconds) all was fine and never had another battery light. Winter tune this weekend will include removing batt connections and cleaning everything up there and an inspection of that big wire running to the fuse box. Just hope my piggy bank can handle ordering a new propshaft for the thing.

Post by **cn90** » 03 Oct 2012, 13:46

A word on Bosch alternator...Many years ago, you could buy a rebuilt Bosch alternator and trusted the local supplier that it was properly rebuilt. Those days are gone. Very often the Bosch alternator you get from Autozone, O'OReilly is crap shoot. They rebuilt with poor-quality Chinese made parts.

Why do I say that? This is because the rebuilders typically open the alternator and anything "looks" good, they keep them.
People often buy the Autozone Bosch alternator only to find out it is bad from the box.
Q.C. is very poor on these rebuilt alternators.

At 177K miles, the alternator is on borrow time. If you only drive around town, then don't worry.
But if you leave town frequently, I recommend that you rebuild the alternator to avoid being stranded in the middle of corn field. Rebuilding an alternator is much easier than people think.

You will need:

* FRONT bearing.....It is either 17x52x17mm or 17x47x14mm. You will have to get your Bosch PN and search for the proper bearing size (Use only Koyo, Nachi, SKF, or NTN; nothing else).

* REAR bearing....likely 6203-2RS (Use only Koyo, Nachi, SKF, or NTN; nothing else).

* Voltage Regulator....$82 or so:
http://www.eeuroparts.com/Parts/PartDet ... amNumber=9

This is Alternator DIY from BMW E39 but the idea is the same for Volvo:
http://www.bimmerfest.com/forums/showth ... p?t=454325

Useful video:

ONV70XC · Post by **ONV70XC** » 03 Oct 2012, 16:40

cn90 wrote:A word on Bosch alternator...Many years ago, you could buy a rebuilt Bosch alternator and trusted the local supplier that it was properly rebuilt. Those days are gone. Very often the Bosch alternator you get from Autozone, O'OReilly is crap shoot. They rebuilt with poor-quality Chinese made parts.

Why do I say that? This is because the rebuilders typically open the alternator and anything "looks" good, they keep them.
People often buy the Autozone Bosch alternator only to find out it is bad from the box.
Q.C. is very poor on these rebuilt alternators.

At 177K miles, the alternator is on borrow time. If you only drive around town, then don't worry.
But if you leave town frequently, I recommend that you rebuild the alternator to avoid being stranded in the middle of corn field. Rebuilding and alternator is much easier than people think.

You will need:

* FRONT bearing.....It is either 17x52x17mm or 17x47x14mm. You will have th get your Bosch PN and search for the proper bearing size (Use only Koyo, Nachi, SKF, or NTN; nothing else).

* REAR bearing....likely 6203-2RS (Use only Koyo, Nachi, SKF, or NTN; nothing else).

* Voltage Regulator....$82 or so:
http://www.eeuroparts.com/Parts/PartDet ... amNumber=9

This is Alternator DIY from BMW E39 but the idea is the same for Volvo:
http://www.bimmerfest.com/forums/showth ... p?t=454325

I had to order one from Autozone "in the middle of the corn field". Now I'm puzzled because the minute I started driving car, it was very rough and when I got home I check everything I suppose to check in case if I broke something during removal replacement: vacuum lines, spark plugs, coils, B+ voltage drop... Everything checked out negative. The last test I'm about to do is to drop serpentine belt and start car and see if rough idle is still there only on battery. I can even technically engage tranny and drive to the point where the idle is roughest @1500rpm+. I will have to do it close to Autozone parking lot in case the battery goes dead. I suspect rectifier may be a culprit to drain reverse current over the normal diode tolerance that may give some rough idle. Sorry for hijacking this discussion, but being curious want to see what cn90 will answer.

Post by **coflynn** » 03 Oct 2012, 17:07

parts of my post at https://www.matthewsvolvosite.com/forums ... =9&t=51058 may be useful... for a diff alternator/regulator so I don't know how much of it is relevant!

Post by **cn90** » 04 Oct 2012, 09:59

ONV70XC wrote:I had to order one from Autozone "in the middle of the corn field". Now I'm puzzled because the minute I started driving car, it was very rough and when I got home I check everything I suppose to check in case if I broke something during removal replacement: vacuum lines, spark plugs, coils, B+ voltage drop... Everything checked out negative. The last test I'm about to do is to drop serpentine belt and start car and see if rough idle is still there only on battery. I can even technically engage tranny and drive to the point where the idle is roughest @1500rpm+. I will have to do it close to Autozone parking lot in case the battery goes dead. I suspect rectifier may be a culprit to drain reverse current over the normal diode tolerance that may give some rough idle. Sorry for hijacking this discussion, but being curious want to see what cn90 will answer.

If the roughness happens after changing the alternator, then yes, it has something to do with your installation.

If you still have the factory alternator, then use it to rebuild.
-For $107 (VR is $82, bearings are about $25 total for both), you now have a very quality alternator that you can trust for the next 150K miles.
- Rectifier hardly ever goes bad.
- Also don't worry about slip rings, see the BMW link above, at 150K miles, the Bosch slip rings still looked OK.