On Fri, 29 Nov 2019 01:23:38 +0000, ss wrote:

Anyhow I opened it up and there is a sensor and then an LED `bulb` which
comes on when activated. Is the LED light necessary for it to operate

Probably not but what does "... there is a sensor and then and LED
'bulb' ..." really mean? I read it that they are in series so simply
sniping a leg of the LED would stop it working.

However I suspect the sensor is connected across +v and gnd with an
out put that goes high for a second or two when triggered. The LED is
between output and ground, possibly via a resistor, sniping a leg in
this case will just disable the LED.

Think I'd have a switch of some sort (twisted wires...) so the LED
can be enabled to facilitate a walk test. Though if the Rx is battery
powered you could just carry that.

--
Cheers
Dave.