how can i add a sensors to a dei alarm?

Hello everyone, I am new here so bare with me please. I have a Python 990 alarm system in my 93 Toyota Celica. Regrettably, in more than one way, I had it installed by Circuit City. Now I am looking to install a second Stinger Double Guard Shock Sensor in the rear of my car. I was told in another place, that if I wanted to add sensors, all I would need to do is splice them together. Well, now I've tried that and neither of my sensors will work.Ive tried them together as well as separately with two different harnesses. I can not for the life of me get them to work. They Light up, but the brain doesn't seem to be getting the signal. Was this the correct way to go about adding another sensor? Are my sensors broken now? Is there a different way to add sensors? I would like to have at least one of the shock sensors up and running as soon as possible. Thanks

I'm not sure if I waited 60 seconds or not, I'll go try that now. Another thing is that the sensors do not have all 4 wires going directly to the brain. The green one on the sensor it self loops back to the blue one which goes to the brain along with the red and black. Then the green one is either coming into or going out of the brain to some other location which I haven't been able to locate.

Hi, I just wanted to give an update. I waited 60 seconds, then tapped on the sensor and it took a second, but it did trigger the alarm. Now I'll go try it again with both sensors spliced together. Thanks a bunch for the assistance.

The green wire you're referring to would be coming from the brain side of the alarm, this wire make it easy to add on a sensor without diode isolation! Also when you conduct your test with both sensors spliced together, if they don't respond you may have to diode isolate!commit your way to jehovah and he will act in your behalf. psalms 37:5

I have no idea what diode isolating is, but it is not needed apparently. I spliced the sensors together again and both tested wonderfully. I was just being too anxious with my original testing. Now in order to get the extra sensor to the rear of my car, I am going to need to add quite a bit of wire to reach the brain. Is there a limit to the length of wire I should run? I have a lot of 14 awg wire lying around. Do you think it will be acceptable, or should I go buy some of that is the same awg as the sensor (22 I think)?

Use slightly thicker to accomodate the extra length, so your 14 should be adequate.

go to a shop that sells alarm and get the sensor. pull the shock sensor out and put the other one inboxead78