74 K10 Dome Light Issue

[Karnage]

Hi there, I recently got me a 1974 K10 and have been enjoying myself quite a bit since then. Like most older vehicles, it has a few things here and there that needs to be fixed. But overall, it's in good condition and I got it for a good price. The last owner before me mentioned that the dome light does not have a bulb and he never tried to get a new one since there is still a light under the dash that comes on when you open the doors. I went to an auto store a few days ago and figured out what kind of bulb I needed. Apparently the owner before the last owner changed it so it took a different bulb from what the auto store found as the "dome light". The bulb that it does take looks like this:

http://tweetys.com/images/products/detail/90bulb.jpg

I checked the wire to the dome light and saw no issues with it. If anything, it's a fuse. But before I start replacing fuses, is there a way to turn on the dome light without opening your doors? There is a way to turn on the light that is on the bottom of the dash and I would think the dome light would come on the same way, but it doesn't. I don't have any issues with the dome light not coming on when I open the doors, as I said, there is already a light that comes on under the dash. I just want a working dome light when I really really need to see inside my cab. I would appreciate some help!