2 questions, fm remote & diodes

My mistake Blue/Black wire.

The ribbon wire from the antenae plugs into the other end of the FM module. The opposite end that has the 2-3 wire plugs

Hi Guys,

I can help you with the diode problem.  There is usually two modes (dual modes/zones) in a sensor.

One of the lines coming out of the sensor is usually a warning line (zone 1) that causes the alarm just to chirp or give a warning when that zone has been violated.

The other line (zone 2) will trip off the alarm, usually instanttly.  If you have two or more sensors, you will need to diode "OR" the zone lines together.  Diode "OR" means sensor 1 "OR" sensor 2 will trip the associated line going back to the alarm controller.

Typically alarm controllers look for external pull down command (grounding) of the sensor lines to trigger an alarm or warning.  The sensors provide these pull downs to the alarm controller.

If you are using more than one sensor, like a shock sensor and also a microwave sensor, you will need to diode "OR" the lines together back to the controller.

If you are only using one sensor, you dont need the diodes.  If you are using (2) sensors, you will only have to add diodes on the 2nd sensor, but its okay to add diodes on both if you wish.

Obtain (2) 1N4001 diodes (available at Radio Shack).  Connect the first sensor (both lines) directly to the controller.  On the second sensor, if it has only one output to the controller, most likely that is a line that will trip the alarm instantly.  If there are two lines, one will be for a warning line and the other for an instant alarm trip.

From the wire(s) at the end of the 2nd sensor, solder one wire onto the lead of the diode that has the band at one end.  This is the cathode lead of the diode.  When the sensor makes that line goe low, the diode will be forward biased and allow the ground to pass to the alarm controller. The other lead of the diode (anode) will get soldered to the wire of the other sensor that is tied to the alarm controller.  Zone 1's of each sensor are tied together with diodes and Zone 2's of each sensor get tied together.  You want warning lines to be tied with warning lines and instant trip lines tied with other instant trip lines. Dont mix the two or you will have chaos!

I prefer to put shrink wrap over all of my solder connections, but electrical tape is fine too.  When you splice into the existing (1st) sensor line, all you have to do is remove about 1/8" of the insulation and wrap the anode lead coming from the second sensor around the exposed wire and solder it.  Again use shrink wrap or electrical tape over the soldered connection.

You will also need to piggyback (tie together) the power lines of each sensor, typically red to red, black to black.

Okay, so what do the diodes do?  They allow each sensor to trigger the alarm controller but they become isolated from each other.  The controller sees both, but each sensor does not see each other and will have no affect on each other.

If the controller uses pull up commands rather than pull down commands, all you do is turn the diodes around with the band facing the controller rather than the sensor.

Use diodes on each additional sensor added.  Again, the first sensor does not need them.  Use diodes on 2 or more sensors.

I hope this helps.

- Jim