that two of the relays apply 12V and ground to make DOOR LOCKS HACK
the window go up, and the other two relays apply To unlock the doors via computer, I had to figure
ground and 12V to make the window go down. out how the switches work in my Caravan. After
My friend developed an onscreen interface for pulling the right door panel off, I disconnected the
controlling my windows, and I bought an ADR2010 lock switch and used an ohmmeter to test all three
controller board from ontrak. net. It has simple positions: off, up, and down. I found that it usually
command language for turning ports on and off has a 20Kohm reading, but that it drops to 2Kohm
and was ideal for this application. when I “unlock” the switch and 4Kohm when I
Using my in-dash touch screen, I can control the “lock” the switch.

ADR2010, which activates the relays I’ve connected I used the voltmeter to measure the voltage of to the parallel port, which in turn can switch the big- both lines that went to the switch, with respect to ger relays that control the windows. ground. One terminal was on the ground of the car,

98765432

1.5V Latching Relay

Resistor

Pager (Call to power up computer)

1.5V Battery

Parallel Port (on back of motherboard)

2. Door Lock

3. Door Unlock

4. All Windows Up (Normally Down)

5. Activate Front Right Window Motor

6. Activate Front Left Window Motor

7. Activate Rear Left Window Motor

8. Activate Rear Right Window Motor

9. Turn Off Computer

5V Reed Relay (Door Lock)

5V Reed Relay (Door Unlock)

T22

D21

R F7

F7

25R

D5

45R 45R

R52

25B 51GF

D23

7F 5R

12D R44

R44

FG15 B52

D21

R5

FG15 B52

R52

D23

5

5V Current 12V Current 12V Car Battery

5V Reed Relay (All Windows Up Normally Down)

5V Reed Relay

(Activate Front Right

Window Motor)

5V Reed Relay

(Activate Front Left Window Motor)

5V Relay

M1-ATX 12V Power Supply

5V Reed Relay (Activate Rear Left Window Motor)

Power Switch

5V Reed Relay (Activate Rear Right Window Motor)

Computer Motherboard

5V Reed Relay (Turn Off Computer)

Wireless Card