problems with led scanner

aight here's the deal.....i just installed my led scanner on my car..the way i connected was i cut the stock led which had only a red and black wire...so black to black...red to constant power(so i connected it to the yellow wire behind my radio...and yellow to the red....it works but the designs won't change..it only blinks..even when i press the button...also when i added another led scanner i connected to the same wires that i previously install the first scanner...and then both of them do not work....i tried them both on a 9 volt battery and both works....so i was wondering what i did wrong...thanks

the output of the alarm is a pulsed power to the l.e.d. itself. so when you hook up the scanner to the l.e.d. wires the power (red) is technically "flashing" the power to the scanner, thus not supplying enough current to be able to change the scanner patterns. in short it's like setting the vcr's clock then unplugging it do it like this......re connect your alarms l.e.d, then place your scanner where you want it mounted. get your ground, ignition, and 12 volt supply from either your stereo, or under the dash at the ignition harness,with your other alarm connections. this way when you turn on the car the scanner shuts off, and when you shut the car off the scanner works, regardless of weather or not the alarm is armed....and you can control the scan patterns. i hope i helped.

sorry i double posted...my comp was messed up so i didn't know if it went though

it will shut off when the car is started, and turn on when it's not. it will work regardless of what the alarm is doing.......real good if you forget to arm your alarm.sweet.

im sorry but im new at this......so i am gonna connect the red wire to the constant power behind the radio with is yellow....connect the black wire to the black behind the radio and the yellow to an output from your alarm that is negative when armed.....where is the output located...is it one of the red or black wires connected to the stock led that comes with the alarm...