I tapped into the power leads going to the tire pressure monitor/homelink transmitter (black module in front of ceiling lights) to power my Valentine 1 radar detector. Soon after I connected the wires, my tire pressure light came on which made me think I bungled something up. I referred to the manual which said it would turn on the light if the pressure dropped 25%. I checked the pressure in all four tires and found they were all 30 psi - a little low but not 25% low. I checked my wiring again and found no problems.

So, I inflated the tires back to 34 psi and the light went out - nice. Since the temps here in TN have dropped about 20 degrees in the past three weeks, I figure this is enough to drop the tire pressure a couple psi. I'm happy to know the tire pressure monitors are that sensitive and work well.

 

My wife was driving home from work last week and informed me that her indicator light for the tires had come on. I checked her pressures and they had fallen to 29psi on two of the tires and 30 .5 on the other two.
I filled to the proper psi on all four and the light has not come back on.

Considering the cost of having to replace the tires due to lack of proper inflation, I don't mind if they are oversensitive. I would rather not let them run underinflated.