I have an '89 240 wagon and when I turn on the blower/fan I get a high pitched noise from what I think is the fan. I am able to turn the fan motor off and the noise ends. I have the dash apart and I am not able to pin point the fan or the source of the noise. Any thoughts on where to look.

A common problem. Fan bearings. It's a lot of work replacing the fan motor. Suggest you try oiling them first. You can try pooping off the front rocker switch panels in the console. Behind you'll see the white blower assembly. Try drilling a large enough hole so that you can get some oil onto the shaft near the motor. Hole can be patched with duct tape for future access. Run fan. If noise goes away than problem temporarily solved. (Depends on oil thickness and bearing wear.)

Replacing the fan is the usual way to go. The fan has two blades, one on each end of the motor shaft. It's in the exact center of your dashboard. If you could magically reach straight in from the "Defrost" pushbutton, you'd hit the fan about a foot in.
Unfortunately there's nothing easy or magical about gettign it out. First you should go get a fan motor for it. Or mail order one, you've got some disassembly time before it gets here. The two fiberglass side covers have to come off the heater box.
Here's a page describing dash disassembly.
http://www.homestead.com/volvo2/Dash.html
The second page has a great picture of what's under there. The clips come off all the way around the airbox sides, and then you unclip the fan blades, unscrew the motor and plug in the new one. I did mine (somewhat less disassembly from what's shown there) in a little under 6 hours. Shops charge 10 hours. So you can save yourself a lot of $$ for a day's worth of work.

"Installation is the reverse of the above." - Chiltons
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Rob Bareiss, New London CT ::: 86 244DL, 87 244DL, 88 744GLE, 91 244: 808K total

Most likely, the blower motor bearings (which are actually sintered bushings) are dry.

You can replace the blower motor, or if you're a cheap Yankee like me, you can disassemble the motor, clean it up, re-lube the bushings, and reassemble.

I did that 6 years and 85k miles ago on my '86 and it has been fine since.
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Don Foster (near Cape Cod, MA)