Thanks all! So, weird, but had the car towed to my Volvo indy mechanic. They could not start it in the lot. They pushed it into the garage, and then it started. Has been starting since. Not sure quite what to make of it.

First things first, check the battery and its connections at the +/- terminals of the battery. Seems unlikely since they are coddled in the clean confines of the cabin, but I've seen it before. Remove, clean and re-install.

-Will
--
XC60 / Odyssey

I looked at the 2007 V70 starter circuit and the starter solenoid is driven
by a fused relay (2/35). (11/B6) = fuse

In the heavy 12V lead from the battery to the starter motor there is a Jump Start connection 17/17, Check that out too.

There is a connector 54/1B between the relay and the solenoid
that looks like a starter service socket. That's where I'd try to put
+12VDC from the jump start connector, to see if it starts.

I have had two V70 starters die when the wire from the main body of the starter to the solenoid broke. Check for voltage on the thin wire with the push connector while a helper turns the ignition to start. If you have power there, suspect the starter.

Good luck!

Hmmm. The dash and headlights work with a minimum of 9V, the starter needs 11V+, BUT you didn't even get a "click".

That could be the switch. It could be the lock out switch, doesn't know it is in P or N. Check your brake lights, if they don't work it could be the brake pedal switch failed (brake must be depressed in order to engage starter).

Do the headlights dim when you try to start the car?
--
-- '96 850T at about 240K, 2005 XC70 at 100K, 1999 V70 at 200K; gone but not forgotten '97 850T5, '83 244 DL, '81 245 and '64 Amazon

Bad ignition switch?
--
Will I buy another Volvo??? We'll see....