If you are getting a fuzzy picture you're getting close (I know that don't sound right' but it is).
1) on the back of the TV and/or VCR, there should be a tiny switch (you'll need a flashlight) that will look something like "CH 3/4 [o ]" (that last part is supposed to be the switch).
2)If both the TV and VCR are set to the same channel (see above) when you select "VCR" the VCR tuner will be in control and when you select "TV" the TV tuner will be in cotrol.