I just got back from a trouble-free 5,000 mile cross country trip, and my 99 V70 T5M now reads 156,000 miles. As I was blasting across Wyoming and Nebraska at 85 MPH, I started wondering how close I was to wearing out the (original) alternator brushes. The thought of needing Volvo parts in Nebraska was not a cheery one.

I'm thinking that it would probably be smart to proactively replace the brushes, either by replacing the regulator / brush module (~$120) or a rebuilt Bosch or REMY alternator ($130 - $160 from Rock Auto).

Unless you guys can tell me that the brushes tend to last 200,000 miles???

At 185,000 all my lights began fluctuating "normal-to-low" so I assumed the regulator was shot. Even though I've read the regulator is external I decided to take the alternator out and bring it to a local alternator shop.
I assumed replacing everything including bearings, pulley freewheel, regulator and brushes at 185K was smart.
It's a 3rd generation shop which I feel blessed to have near me. Rayelco in Lodi, NJ.
It cost $135 and was ready the next day.

https://www.amazon.com/Volvo-Voltage-Regulator-Bosch-30667899/dp/B00A79WPRA

Look around for lower prices on voltage regulators, so long as the bearings in the alternator are still good.

There are some old timer alternator shops around that might replace the brushes for $20 or so, but then you have to worry about the regulator going bad... There is always something to worry about.
--
Keeping it running is better than buying new

IPD has a replacement regulator/brush pack for around $45. Based on my experience, you are just about due for one based on your mileage!

While you're at it, measure for voltage drops on the battery cables and the B+ cable from battery positive to the fuse box (the failure rate on these cables is very high-- often you can feel them getting very hot after the car is running for a while).

Good luck!

I'm not seeing the brush kit on the IPD website. Can you post a link?

https://www.ipdusa.com/products/7297/115079-brush-pack-voltage-regulator

So are you telling me the alternator in my 850 at 250k is on borrowed time? I've never touched the brushes, regulator or any of the cables...:)

I sold my '95 855T with the original alternator at 220,000 miles wondering how long it would last!

Erwin

The alternator is pretty different from the '99+ cars, but yes! It seems that the cabling problems are endemic in the '99+ cars-- the earlier ones seem better...