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Old 08-06-2012, 06:59 PM
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TerminatorX5 TerminatorX5 is offline
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I am not sure what the specs of your relay are, but you need something that will draw minimal amount of juice, as the LED green light that illuminates inside the PDC button on the front center console (module A169) draws just few milliamps, thus the output on the Pin 7 is a very low wattage, creating a super small amperage.

When you tap that wire, you dillute the flow of the current in two directions, one is to the original destination of the LED and the other one to coil of the relay. If the resistance of the coil is too low, it will draw a lot more juice, and essentially will shunt the other wire going to the LED, and as a result, will disrupt the operation of the PDC module.

The relay that I use, is a very small and is using just a fraction of the current that is coming on the Pin 7, and such, will not disrupt the PDC operation. If i had willpower and energy, I would have gotten the one that is Sensitive, and draws instead of 37 mA just 17 mA. Most automotive relays sold have rather higher level of triggering amperage. I have attached a datasheet for the one I was talking about.

The relay contacts applied groung to the special pin on the OE TV module (pin 17 on X18804), that supercedes anything going to the front monitor and displays image that is coming to two other pins on the same OE TV Module (X18806 TV Module, Pin 13 (+), pin 14 (-) from reverse camera). the relay did not apply power to camera, the camera was already powered from an ignition hot source in the trunk lid, it merely opened the gates for the signal to go to the monitor...

_________ LED in the front (A169)
l
l
(+ Pin 7)-------HrelayH------(-)ground
X300 coil chassis
PDC

The closing contacts of the relay go to (-) Pin 17 on X18804 (TV Module)
and to ground (chassis)


Do you have a factory TV module installed?
Attached Images
File Type: pdf datasheet relay rear camera.pdf (80.3 KB, 340 views)
__________________
E53 X5 4.6iS
147K mi - Sold May 2013
Tireprints left in:
USA, Nicaragua, Costa Rica, Panama, Russia

E53 X5 4.8iS built 2005-10-17
66200 mi - June 2012
96000 mi - June 2013
112000 mi - June 2014
OEM fire extinguisher
OE first aid kit
OE tow hitch
OE TV module
OE aspheric mirror
K&N air filter
black/white badges
rear camera
4-channel video recorder

Here is the list of things I have done to the X
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