I just finished replacing my Volt regulator on my 97 850 and my symptoms got worse. It was having wildly fluctuating readings (it would be 12.6-13.8, but mostly 13) and finally the lights started to dim the other day. So I bought a new volt regulator.

After finally having a chance to install it, I start up the car. But now it's reading MUCH lower (10.6), and I'm getting a ton of idiot lights.

The alternator potentially has (approx) 180K on it, but the grooves in the shaft that the regulator rubs up against, aren't significantly bad/deep/worn.

But I wonder if maybe they're worn down enough (the valleys) that the new pads on the new regulator aren't making enough of a contact to create the juice needed to charge the battery?

But wouldnt the grooves have to be really deep for that to be an issue?

I'm in the process of taking the new volt regulator off (again *grumble*) and seeing if that is an issue. I'm also thinking of putting the old one back on and see if it works again (such fun!).

Any tips/suggestions (outside of just buying a new alternator itself)?
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1985 245. 246K Gone..but not forgotten. Sold in 2013, found 2018! Still running on the road. Of course. 1993 Volvo 850 soon to be gone

well that was quick.

took off the volt regulator (much easier the 2nd time...). One of the brushes completely broke off. How I'm not sure, but it's was only making a connection with one of them.

I've contacted the seller, hopefully they'll be able to help me. The fact I'm going to be without my car for who knows how much longer is only a minor set-back (compared to having to replace the alternator itself...bot in cost and time).

Oh well, not like I was working this week much anyways. :)
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1985 245. 246K Gone..but not forgotten. Sold in 2013, found 2018! Still running on the road. Of course. 1993 Volvo 850 soon to be gone

Second time is alway faster! Wait till the third time... that"s when you drop the Philips screwdriver and it lands in a totally inaccessible place!

Why not put the old regulator back in? At least you know that the car will run.
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Keeping it running is better than buying new

I'm going to see what the seller says (I have a second car anyways) before I decide if I want to put the old one back in.

And you're correct about the screwdriver thing. As any Volvo owner knows, they LOVE disappearing on us in the engine compartment..or under the seat. Or trunk...or....
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1985 245. 246K Gone..but not forgotten. Sold in 2013, found 2018! Still running on the road. Of course. 1993 Volvo 850 soon to be gone