I think i figured it out:
Ok the 4PDT relay has 4 rows of pins.
The first three rows have 4 pins each.The 4th row of pins has only 2.
You can see that the 3rd row is slightly farther from the first two rows
------------
| o o o o | ---connect to navigation computer
| o o o o | ---connect to AVC RGB1
| |
| o o o o | ---connect to the navi monitor
| |
| o o | ---connect to a switch then to power source, ground
|_______| the other pin
the first row(top) of 4 pins in the 4PDT relay are connected to the navi computer because this is the circuit that is always on when there's no power/current being applied to the relay, meaning the relay switch is turned off.
the second row of 4 pins is connected to the AVC-RGB1.That's because this circuit is not connected to the monitor when the 4PDT relay is switched to off.
If you turn on the switch that powers the relay, the image on the screen will switch from navi comp to RGB1 video source. That's because an electromagnet in the relay is activated when the power on the relay is swithed on. This will then pull the 4 metal contact switches(inside the relay) and disconnects signal from the navi computer . These metal contacts will then connect to the video signal (3rd row of 4 pins) coming from the RGB1. In turn the monitor will display the video from the RGB1.
Whew! Actually I just figured this out by staring at the 4PDT relay and look what's inside and found out there's 4 set of metal strips in between the 1st and 2nd rows of 4 pins. And there's an electromagnet that looks like a spool of thread. There are 2 electromagnet's wires that are connected to the 4th row with 2 pins--which means connections to power source to activate the electromagnet.
anybody is welcome to pls correct me if my analysis of the relay is wrong before it's too late for me. Thanks. I'm doing this tomorrow.
Thanks
Ok the 4PDT relay has 4 rows of pins.
The first three rows have 4 pins each.The 4th row of pins has only 2.
You can see that the 3rd row is slightly farther from the first two rows
------------
| o o o o | ---connect to navigation computer
| o o o o | ---connect to AVC RGB1
| |
| o o o o | ---connect to the navi monitor
| |
| o o | ---connect to a switch then to power source, ground
|_______| the other pin
the first row(top) of 4 pins in the 4PDT relay are connected to the navi computer because this is the circuit that is always on when there's no power/current being applied to the relay, meaning the relay switch is turned off.
the second row of 4 pins is connected to the AVC-RGB1.That's because this circuit is not connected to the monitor when the 4PDT relay is switched to off.
If you turn on the switch that powers the relay, the image on the screen will switch from navi comp to RGB1 video source. That's because an electromagnet in the relay is activated when the power on the relay is swithed on. This will then pull the 4 metal contact switches(inside the relay) and disconnects signal from the navi computer . These metal contacts will then connect to the video signal (3rd row of 4 pins) coming from the RGB1. In turn the monitor will display the video from the RGB1.
Whew! Actually I just figured this out by staring at the 4PDT relay and look what's inside and found out there's 4 set of metal strips in between the 1st and 2nd rows of 4 pins. And there's an electromagnet that looks like a spool of thread. There are 2 electromagnet's wires that are connected to the 4th row with 2 pins--which means connections to power source to activate the electromagnet.
anybody is welcome to pls correct me if my analysis of the relay is wrong before it's too late for me. Thanks. I'm doing this tomorrow.
Thanks