Anyone with experience with aftermarket alarm systems, I need help here...

I have a Crimestopper CS-2015 pager alarm system. Works nice when it's warm, but when I try to do anything with it when it's cold out, I have to put the transmitter right up against the glass next to the antenna for it to work. Now, once the alarm is disarmed, it chirps twice. This is normal. However, once I get the car to unlock and the alarm to disarm when it's cold out (by putting the transmitter on the glass), there is an unusually long pause between the chirps from the siren. Normally it goes *chirp, chirp,* but when it's cold out it sounds more like *chirp..............chirp."

I know it's not the transmitter, since I've tried both of them and one has never been used. Batteries are fairly new in each. I also know that it's got nothing to do with dirt, snow, etc. on the car, because it does this when the car is spotless, and it's beautiful (but cold) outside.

Now here's the kicker...after I drive the car a while, and it warms up, the transmitters work at normal range again . Also, once warmed up, the chirps from the siren are normal, and there's no pause in between. What's going on? All I can come up with is that the receiving unit for the signals is affected by cold temps. I called Crimestopper about it, and they said to just send the transciever (connected to the antenna inside the car) back and they'll replace it. I just wanted to get more opinions on it before I do anything. What do you all think? Should I send the brain back too? Any input would be appreciated!

Sorry if this made no sense, but I didn't really know how to describe it that well...

 

I'm not gonna say that this is the problem, but electircal devices which work off batteries tend to have less power available when cold. Think of your car battery for example. Everyone knows that in cold weather, your battery doesn't have as many cranking amps as it would if it were warm. It may be that your car battery just don't have as much energy available to receive transmission from your transmitter like it would if it were warm. (like you said, it work normal after the car has been driven) This is also true for the difference you hear from the chirps. Less power=slower chirps and transmission. I hope this makes sense. I think I might have even confused myself.

 

you can find the receiver in the car and lengthen the wire so it spans across the car a bit. it would not be the receiver unless the battery in the receiver is dead, but if it isnt dead the cold weather should help it more then hurt it because...if my physics are correct the air is more dense in cold weather providing radiowaves to travel faster and quicker. but then again i failed physics...

 

It is possible that some of the components in the alarm / receiver box are changing their electrical values when they get cold. Capacitors, especially, are prone to drifting with temperature.

This can throw the 'tuning' of the alarm's receiver off a bit, like being slightly off station on an old radio with a dial tuner. That decreases range significantly.

I would hope that a manufacturer would spec components that are good over a wide temperature range for something that is to operate in a car, but sometimes they cut corners.

 

Thanks for the replies everyone...I know that batteries lose some power when it's really cold out, but it shouldn't affect the range on an alarm, at least I wouldn't think so. My old Alpine alarm never seemed to be affected by the cold. The battery in the receiver couldn't be dead, cause it doesn't have it's own battery - it's wired straight into the car's electrical system, and that never fails to start the car. Maybe some of the electrical components in the transciever are changing values...I seem to remember learning somewhere that resistance and capacitance changes due to extreme temperatures. Maybe that's affecting it. What I'm gonna do is take out the transciever in the car, and maybe the brain as well, and send them to Crimestopper and have them send me new ones, and I'll see if that fixes it. Hopefully they've caught this problem and fixed it since they put my system together. I'll let everyone know how it goes!