I found a Mac hardware FAQ from 1997 on www.deja.com that states:
"The IIci is the only Mac with built-in video that absolutely cannot drive a VGA monitor." So Byron is right and it won't work.

On 3/27/2000 at 20:07, wbdesnoy@ucalgary.ca (Byron Q. Desnoyers Winmill) wrote:
> Hello,
> 
> I think that the answer is no, the Apple Basic Color Monitor will not work
> on the IIci.  I have been told that the IIci does not support VGA displays,
> and the 60Hz refresh rate of this monitor sounds like VGA to me.
> 
> Byron.
>  
> > > I need to know if my monitor I'm using with my LC III will work with the
> > > onboard video of a Mac IIci. The monitor I have, on the back says,
> > > "Apple Basic Color Monitor". Coming from the monitor is a plug that has
> > > 3 rows of 5 pins, although some of the pins are just not there. This
> > > goes into an adapter that converts it to standard DB15, that goes into
> > > the computer. Does anyone have any info on this?
> 
>