02 V70 Byte Exchange?
 

Hello,
I just bought a 02 V70 from an auction last month and I really enjoy it, it’s the first Volvo I’ve owned.
As it’s getting warmer, I’ve been cautious of any overheating issues...as my last few vehicles were plagued with them. I noticed in the past when I ran my A/C, then what I thought was the interior fan would run for 10 minutes or so after powering the vehicle off....which I saw in here was normal.
Today I did not run the AC, and the “interior fan” was running for 30 minutes after powering off, which led me to discovering the noise coming from the byte converter box. It actually just now shut off as I’m typing this, so it ran for about 35 minutes. I have no idea what a byte converter does...it looks like some hard drives but the picture makes it seem like there are belts inside them. Give me some slack guys, it’s also the first Euro car I’ve owned. Bottom line, is this normal? Or should I start looking into things?

Preciate Ya,
Nervous

Byte converter box? (I thought bytes referred to 8 bits within a word). The area you are talking about is the byte exchange sticker near the timing belt/serpentine belt - it can be used to indicate when the belts were last serviced. There's also an air distribution hose (the one with the pleats) to send cool air to the ECU. This doesn't have a role in your cooling system. The fan is relayed to allow it to run after the key is offer and is on a timer. Usually the cause of excessive run on can be a faulty ECU temp sensor, a sticky thermostat or a clogged radiator.

Given this car is new to you, I'd do a few things to service the cooling system:

1) inspect all hoses, radiator seams, and overflow reservoir for leaks or signs (ie whitish deposits) etc.
1) drain the old coolant out and do a demineralized water flush (don't use after market radiator flush products as they may harm the aluminum components)
Refilll with the appropriate 50/50 coolant (avoid Dexcool - usually the coolant for older Volvos is green)
2) replace the thermostat, engine coolant temp sensor (its under the thermostat housing so easy to do both at once)
3) replace the overflow cap (its a pressurized system so the caps can fail over time)