I'm really not sure if the stock sensor would work or not. Adding my board may or may not affect how the sensor in your dash reads as well. I'm also not sure what voltage the stock sensor uses (pulsed 5v, right?)

Like Andrew mentioned, you could hook it up, wait until the car gets to temp, then turn the pot down until the fan comes on (or until the status LED turns on, to see if it'll work). In fact, due to the small differences in temp sensors, this may be the best way for everyone to set the turn on temperature.


For the o-scope, here is the one I was thinking of getting. link

To use it, basically just need to hook one probe each to the trigger and tach lines. The software has a few settings, but by playing with it you should be able to figure it out. It looks like it does have the option to export/save data. I'd just need a copy of the waveforms at different fan speeds. Basically, put your special harness in between the fan and the plug in her car, then let it idle and warm up in the driveway. Capture some data at different speeds and you're done.

If that sounds like something you'd be willing to do, I'll get the oscope and we can go from there.