How to: Under Door Light - Page 8

reconjb · #**106** 04-25-2014, 03:58 PM

Quote:

Originally Posted by friskjs

this is a greeeat idea! i would like to do it someday. and possibly put one under the hood with some kind of pressure switch.

There is a how to for that too ... well pick your own switch atleast

AmericanPride! · #**107** 04-25-2014, 04:01 PM

Quote:

Originally Posted by 10rangersport

Anybody know what the yellow and black wire is supposed to be on a 2010?

Generally speaking, that's 12v and ground

10rangersport · #**108** 04-25-2014, 04:21 PM

Quote:

Originally Posted by AmericanPride!

Generally speaking, that's 12v and ground

I know but I'm talking about what color code of wire

noflers · #**109** 05-30-2015, 12:20 PM

Found these, Zone Tech 30cm LED Car Flexible Waterproof Light Strip WHITE (pack of 4) https://www.amazon.com/dp/B00EKPOG10..._YSGAvb0D9YV09

At $6.99 they look Damn good to me. I do have a question because I'm not experienced in the electrical side of things. If I used all four of these in my truck would my 95 amp alternator be right to handle them?

reconjb · #**110** 05-30-2015, 12:27 PM

Quote:

Originally Posted by noflers

Found these, Zone Tech 30cm LED Car Flexible Waterproof Light Strip WHITE (pack of 4) https://www.amazon.com/dp/B00EKPOG10..._YSGAvb0D9YV09

At $6.99 they look Damn good to me. I do have a question because I'm not experienced in the electrical side of things. If I used all four of these in my truck would my 95 amp alternator be right to handle them? I also plan on adding an efan in the future, would all that work?

Being led your truck won't even know you added them they pull so little

AmericanPride! · #**111** 05-30-2015, 12:34 PM

Quote:

Originally Posted by reconjb

Being led your truck won't even know you added them they pull so little

^^

It'd be like throwing a newspaper in your bed

noflers · #**112** 05-30-2015, 12:36 PM

Awesome. I wanna put them on both doors, and both the driver and passenger for areas

noflers · #**113** 06-03-2015, 04:50 PM

I have all manual doors so there aren't any hot wire I know of, and I'm wondering how I might go about this. Can I get my power from the cigarette lighter? Also, does anyone know which wire is the door switch in a 99?

reconjb · #**114** 06-03-2015, 08:36 PM

Quote:

Originally Posted by noflers

I have all manual doors so there aren't any hot wire I know of, and I'm wondering how I might go about this. Can I get my power from the cigarette lighter? Also, does anyone know which wire is the door switch in a 99?

You can just run a wire from any always hot source to the door lights and it will still work the same

noflers · #**115** 06-03-2015, 08:41 PM

So run the black wire on my strip to the door switch wire (which is which one?), and the red to the cig lighter than?

Jp7 · #**116** 06-04-2015, 10:57 AM

I invented this, you have a critical step missing in your write up.

----------

Quote:

Originally Posted by yfzranger

wired them as shown and to a fused constant power. they will be off when you close the doors come on hours later very dim though so there not gettin all the juice.

the missing step in this incomplete write up will solve your problem

noflers · #**117** 06-04-2015, 11:00 AM

Are you ever going to mention that step, or....

noflers · #**118** 06-04-2015, 11:49 AM

That's kinda weird anyway^^^ cause I'm finishing this up now. Went pretty smooth

Jp7 · #**119** 06-05-2015, 01:32 AM

Quote:

Originally Posted by noflers

Are you ever going to mention that step, or....

You need to add a power diode to the wire feeding the door switch PRIOR to the ground that you have the LEDs on.

This way when the BCM battery saver relay kicks in and the voltage drops the LEDs to not feed back into the BCM.

If you don't do this you are constantly backfeeding your BCM current. The LEDs come on dim because when the BCM goes into power saver mode the voltage drops to about 3 volts (or 5 I can't remember) Your LEDs constantly have about 12 or 13 volts on the hot side and the difference is approximately 9-10 Volts (which is less than the 12 they are designed to run on)

That's why they come on dim.

The kicker is since you are feeding power back into the BCM you can actually damage it - especially if you have a high-current draw LED setup with a low internal resistance when the semiconductors are conducting.

The best way to do this is use the switched ground to feed the base leg of a transistor, which you can use a very high resistance on the base leg (1000 ohms or so) This is not really necessary in these trucks because it is an "open door, closed circuit" setup

"open door closed circuit" is an ancient way of doing it. Modern cars have ground when the doors are closed, and lose ground when the door is opened. So on most modern cars you absolutely need to use the transistor.

Tapping into the dome light is just a dumb way to do this as well. Both sides would come on when the doors are open (even know you wouldn't have a backfeed problem)

Moral of the story here is if you don't understand the electrical system - don't modify it. I'm an electrical engineer with 16 years of experience and I still struggle reverse engineering OEM electrical systems.

http://www.electronics-tutorials.ws/...or/tran_4.html (for those who want to learn more)

noflers · #**120** 06-05-2015, 06:26 AM

So I'm thinking maybe that missing step is important now... I went out to my truck late last night and the door light was on. I opened and closed the door and it turned back off. I then sprayed down the door latch just in case that's what caused it, but when I woke up this morning and went out to it the light was on again. Nothing else comes on except the under door light.