Grounded Temperature switch won't automatically shut off

[nickgorey]

I've seen at least one other person with this issue, but per Timsrv's suggestion, I grounded my temperature switch (the one with the single wire). The issue is that, unlike Tim states, my idle won't drop unless the wire is ungrounded. I even tried it with a different ECU and still no cutoff. Has anyone been able to correct this issue? I've been considering hooking up a switch to manually cut it off, but would love a solution that doesn't require modification.