Chris,
I think virtually all these systems keep the plugs glowing a bit after the dash light goes out. For an easy test try turning the key to glow at night (or in a closed garage) with the drivers door open. You'll see the interior lights dim when the plugs glow and stay dim after the dash light goes out. After a total of 45-60 seconds or so you'll hear a "click" as the relay cuts out and the interior lights will brighten up a bit.

__________________
LRG
1987 300D Turbo 175K
2006 Toyota Prius, efficent but no soul
1985 300 TDT(130K miles of trouble free motoring)now sold