ATI card will not sense older tv as sec. display unless VCR connected, help!

I have been trying to connect my older Zenith television to my ATI ALL
in Wonder
video card as a second display. The ATI card would sense that my
Toshiba tv had
been connected with no difficulty and show it is as active . But with
the older Zenith tv, it will not sense my connecting it unless I run
the connection through the VCR. If I connect the video card RCA out
to the television aux in, the card will not sense the tv and activate
it as a second display device.

zenith tv with four video 'source' options listed in the menu:

antenna
cable
VCR
Y/C

the RCA jacks on the back of the television look like this:

VCR-1 Aux
video: O-------O
audio:
left O-------O
right O-------O
loop

Now that I have put the video card 'out' cables to the VCR's 'line in'
and then put an RCA cable from the VCR's 'line out' jacks to the
Zenith tv's 'VCR-1' RCA jacks, the ATI card in the computer at least
senses that the Zenith tv is connected, but there is still no desktop
displayed by the tv in the Y/C source display.

I have tried using double RCA plugs and splitting the 'line out' from
the VCR.
This is essentially a way of connecting two RCA cables to each 'line
out' (audio and video)
which then gives me two video cables out from the VCR and two audio
cables out from the VCR. I then connected two of the cables to the
VCR-1 jacks, and two of the cables to the AUX jacks. This did not work
either.

Please help with this. This Zenith tv was connected a few years ago to
my computer,
and it worked as a display, but I forget how I had it connected then.

btw, if this is any help:
The wall-cable for cable television is connected directly to the Zenith
tv. It is not being looped through the VCR (as I do not have enough
short cables to loop it)

Also, now that the ATI card senses the zenith, If I directly connect
the RCA 'lines out' from the video card to the 'aux' RCA jacks on the
back of the tv,
it still does not show my desktop display. The screen stays blank.