Re: troubleshooting old alarm, worked perfectly till this am....

[JoeRaisin <joeraisin2001@xxxxxxxxx>]

If the contact is in the bottom of the window, then it is not uncommon
for moisture to corrode the splice.

Pulling the contact out of the frame and checking the leads with a
multimeter while moving the contact, near and then away from the magnet,
will verify whether or not the contact is good or bad.

You can replace it, if you can get the same size and type (from the
picture it is a normally closed device- meaning the contact creates a
short when the magnet is near.

If the contact is bad, shorting the leads the contact is connected to
will,in effect, bypass that window while the rest of the system is good.

If you are concerned about the siren, simply remove the positive lead
from the terminal at the panel.  if it is supervised, you may have to
place a resistor across the terminals.

Really though, the panel you have is pretty old. You can replace it and
the keypad with a relatively inexpensive one that will be much better.
Contacts are pretty generic.