HKC Contact Open

08-11-2025 10:21AM #1

Hi Guys, Hkc slim contact that started showing as open last night when closed.

I thought maby the reed was faulty but checked with multimeter and ive got continuity when closed, its looped to another contact which i checked aswell and is also showing continuity when closed

I popped out the 2 whites on the shock/bridged them but still showing open.

From the other wires is there a bridge i can do to confirm if its the sensor or wiring at play?

altor · 09-11-2025 07:06PM

https://www.boards.ie/discussion/2058428055/hkc-contact-open

You have 2 loops at the above sensor.

If you disconnect the reds and blacks, then join together the red and black for each cable, does the zone in the panel show closed?

The one that closes the loop is the one going back to the alarm panel. The other is going to the second sensor.

If it closes, then join the 2 blacks together, same with the reds and see if the zone closes.

If it does it may be the sensor you have open causing the issue, if not go to the second sensor and join the red and black and see if that closes the zone in the panel.

10-11-2025 03:08PM

https://www.boards.ie/discussion/comment/123975880#Comment_123975880

Thanks for the above, i picked up a sensor this morning and switched wires across but its still showing open, so i did as you saif above but joining red and black (either pair) doesnt show the zone as closed.

I moved onto the next sensor that only has 2 wires in it, again joined red and black but still open.

In total there are 4 different sensors on the zone, ive popped a picture below of the other 2, again i tried red and black together on each of these but still showing open

Something strange that i noticed though was if you inhibit the alarm and set, the zone may randomly show that its closed after a few hours, when i open the door with the sensor that i changed today, it will show open then and stay open when door is closed, incase that is of relevance

altor · 10-11-2025 10:09PM

You may have a short between the tamper loop and alarm loop.

You now have 3 reds at the first sensor also?

Can you identify the cable going to the end device, then check with the meter for a short with sensor lid on.

Then disconnect the other cable in the middle device and close to see if there is an issue with the cable back to the panel.

10-11-2025 11:01PM

The sensor with the 3 reds is the third in line (on a window) theres another on the opposite side of the window with just the black and red, this then seems to loop into the first sensor which i originally suspected to be the issue, the bottom pic above is the end device on the line. Ill check for a short there and see how it goes

11-11-2025 02:35PM

The zone was showing as closed this morning, id opened the door to let the dog out and it showed open, then closed again when i shut it so i thought happy days were sorted (this was the sensor that i replaced yesterday)

Only to open and close it not long ago and its back to showing as open! I have the engineer code for it, its not showing up any faults from the menu there either.

Im wondering could it be somehow firmware or panel related or given the above is it narrowing it down to wiring?

altor · 11-11-2025 03:57PM

https://www.boards.ie/discussion/comment/123980204#Comment_123980204

Not the panel, part cable or a sensor on the loop

11-11-2025 06:08PM

So just to update, worked from the furthest back to a junction where the wires then go underfloor to the main panel and the fault seems to be on the line coming back to the panel.

Theres no spare cores on it to use but what im wondering is with the hkc wirless sensors is it possible to add one at the junction and then wire out of that to the remaining sensors on the zone?

altor · 11-11-2025 08:38PM

https://www.boards.ie/discussion/comment/123980796#Comment_123980796

You could close off the tamper loop in the control panel and use the two cores, if working, for the alarm.

If not working, then you can use a wire free sensor and wire into it.

HKC Contact Open

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