One of two gable vents sealed -- should I cut it open?

[ilyaz]

I have a split-level 2 story house built in 1960 that is shaped like a large T. In one of the sides of the T and its foot, I have to gable vents. Have an attic fan at one of them (the one in the first picture).

The fan died after running for about 5 years. The electrician who installed a replacement told me that the other vent is actually sealed. That is, as you can see in the pix, there is a (very old) vent grille on the outside. But on the inside it's covered up by wooden boards. Sorry, I don't have any pix of the inside. Moving around that attic space is PITA but I'll try to get inside pix in the next few days.

We lived in the house for 20 years and only now found out about this! Questions:
1. Could there have been any good reason to seal the vent opening like this?
2. And would there be any harm in me cutting it open (leaving the old grille in place of course)? I was under the impression that I had to have the vents open on both sides for the attic fan to do its job, i.e push hot air out of the attic by replacing it with colder air from the outside. It seems that what the fan does now is it works extra hard to pull air from the inside of the house that was cooled by the AC. Or am I missing something here?

 

[joecaption]

What are you trying to show the picture of the lint covered screen?
Is there any soffit vents?
No form of roofing will work without plenty of soffit vents.

 

[ilyaz]

I see only one small soffit section (in the photo) that is perforated. The rest of them look solid. Is this a problem?

 

[joecaption]

Keep in mind I'm not there to see it so I'll have to make some guesses, and some may sound rude, there not meant to be.
My first guess is at one point that home had open exposed rafter tails that someone that had no idea what they where doing tried to enclose that area.
It may be just the picture, but I'm seeing unlocked, sagging, buckled panels in that picture.
First thing I would do is go up into the attic and see if I can see day light coming in along that roof line where it meets the outside wall and if baffles have been installed.
Most often with a roof line like this if it started out exposed, there would be blocking between the rafter bays.
If there not removed or at least bored out with 4" holes then that vented soffit is doing nothing.