DSC PG9975 Not Working


Would you know if these door/window sensors are compatible with the IQ4? I installed one and it kept sending false window open signals to the panel.

Another one seems to have been auto bypassed when armed stay. Could it be low battery or just not compatible?


The PG9975 is compatible, but there are some potential issues with units designed for specific systems/dealers. Can you provide a photo of the full part label for those sensors, and box labels?

Also, can you provide a photo of the sensor installed on the window?

Thank you. I will grab the photos of the sensors. In the meantime, I ordered the DSC PG9303 sensors. They claim to be compatible with the IQ4. Is this correct?

Yes, both the PG9975 and PG9303 are compatible. See the list here.

This is the box and back of one of the sensors.

Thank you, I was looking for that 915-3 number. Those should be fine.

One thing to consider is that PowerG uses adaptive battery power. It may take a short time for the device to adjust power levels after pairing.

Can you post a photo of the sensor that was false alarming where it is installed?

Thanks for the quick reply. I took the sensor down due to the problems. One kept reporting the window was being opened. The other seemed ok but then apparently reported to the panel the window was open and it bypassed it when arming. They were just not reliable.

I suspected a better y problem but just thought the battery was old and weak.

The reason I asked for the photo was to check the placement of the magnet, if it is not lined up with the correct spot on the sensor it will have a difficult time maintaining a closed status.

I tried placing them at 90 degrees the first time. Then I tried the side by side placement.

Does the magnet need to be in the middle of the large sensor?

This is likely the issue.

See the manufacturer instructions here.

The magnet must be aligned parallel with the correct side and correct spot where the reed switch is. The sensor cannot properly close when the magnet is not aligned with the right location. There is a small symbol on the side of the housing which indicates where the reed switch is and where the magnet must go.

Thank you. I did read the instructions previously, but to me they do not indicate the placement other than just addressing the gap that is allowed.

Are you referring to this chevron on one side of the sensor?

Yes, the center of the magnet should roughly align with that mark.

Thanks! I feel quite dumb about not realizing that.

I have reinstalled one with the alignment and will see if it works well. This is how it looks:

Yep, that looks good.

No worries, the drawings in the manufacturer manual showing the magnet alignment aren’t to scale and they don’t even place the arrow mark in the spot its actually found on the housing. It could certainly be improved.