I have a 2005 Dodge Caravan se and want to instal a remote entry system. I have done some checking and I dont know how the existing system works. I have a door lock switch on both front doors. It never came with keyless entry. I have checked and it is not a +or - pulse to fire the relays. I took the door panel off and the L/U switch has only 2 wires going to it. Anyone know how the system works and how i can instal a remote entry. Thanks
Doug

 

Your best bet is to find an aftermarket alarm system with keyless entry. If your looking for a factory system, they are not available as an accessory kit because the transmitter for the keyless entry is built into the head of the key. The existing system works with a resistor inside the lock switch that is connected to the body control module, and is put into series with the module when the switch is depressed. It is negative switched with a different resistor value for lock and unlock.

 

Thanks for the info. I have purchased a remote start and keyless entry system. I am not interested in the remote start, only the entry. It works on the - or + pulse system. So my system with the resistor in the switch and put in series with the body control module, the value of the neg voltage going to the module controls a L or U signal. So if i can determine the value of the resistors for the L/U and bought them i could use the system i bought to send a neg pulse thru these resistors. I assume there is a body control module on each door. if not is there one central one and where is it located?
Doug

 

There is only one central control module, located on the firewall to the left of the steering column. 4 large connectors. You need to find 1% tolerance resistors to use to pulse the body module, not available at radio shack. You could probably use the 5% ones available if you live somewhere there isn't huge temperature swings (affects the resistance values and the BCM is very sensitive to the correct voltage). You can't pulse the switches, the switches are the ones pulsing the BCM, you have to run seperate wires into the BCMs existing connection to the door switches. Connector 3 of the BCM (Black/White Connector) there is a violet and dark green wire that is the signal from the drivers door to the BCM, the passenger door is Violet and Light Green. I usually use one wire for the lock and the other for the unlock, to keep the aftermarket module isolated better.