[cadgear]

Do you have the guage or just the dummy light? I think these have a seperate temp sensor mounted on the head for the guage/light, and the ECT just feeds to the PCM. If that doesn't work, yes, it could be in the wiring. Does the engine actually reach critical temp? I would assume not since the light won't come on until 260+ degrees, IIRC, and at that point you start to warp and crack heads...

Fans turn on all right? Known good thermostat? Just trying to rattle out ideas that I've got...