Hi,
I have a friend who has a 2002 Honda Acoord SE 4 cylinder automatic.
When he turns the A/C past the second level say 3 or 4 max position there is a howling noise inside the cabin. I was thinking that it might be the heater fan. What do you guys think? Any help would be appreciated. Thanks.

 

It sounds like the fan to me.

I had problems with a new aftermarket fan for my old accord. The aftermarket fan doesn't have the plug, so you have to splice the wires. My passengers feet would hit the wires and cause problems.

I would get the Honda fan if you decide to replace the fan. Some of the online OEM part sites have them for much cheaper, but you will have to pay shipping. The part number is 79310-S84-A01 for that fan. Ebay is another alternative. A junkyard is another cheap source for parts.

 

It could also be the fan was slightly bmisaligned when installed and fan blower cage is striking the housing. Check blower cage for looseness and obvious problems and carefully re-install. It may fix the problem.

good luck

 

While there, change the cabin air filter and make sure there are not leaves and other items in there.