Even better: get rid of the ligh entity and set a light style for the brush. Here's how:
Set a style of lighting for the texture light. Can be applied to any brush based entity.
Available styles are:
0 : "Normal"
-3 : "Grouped"
10 : "Fluorescent flicker"
2 : "Slow, strong pulse"
11 : "Slow pulse, noblack"
5 : "Gentle pulse"
1 : "Flicker A"
6 : "Flicker B"
3 : "Candle A"
7 : "Candle B"
8 : "Candle C"
4 : "Fast strobe"
9 : "Slow strobe"
12 : "Underwater"
The Grouped setting is essentially a hack to allow your texlights to be switchable. To use it, create a brush entity with texlights on it, and set its style to Grouped; then create a light entity with the same name as the brush entity. Hlrad will now pretend that the light emitted by the texlight is "really" being emitted by your light entity. In other words, turning the light on and off will now turn the texlights on and off, too.
You'll probably want to set the brightness of the light entity to 0.01, so that it emits no light of its own (this trick is unnecessary if you're using Spirit of Half-Life, which supports switchable texlights directly).
You will need the latest version of the ZHLT, which are available here:
http://ammahls.com/index.php?page=home