LED license lights with interior resistor mounting
So I can access the wiring for the rear plate lights to mount a load resistor from the passenger side rear wheelwell? And it's sitting right there behind the liner?
bump:
Raven, did you get that DIY for mounting the resistors done?
I'm trying to get license plate LEDs to work right now, except I have no clear idea 1) where to mount the resistors, and 2)how to wire the resistors. Sorry, mechanical/electrical NOOB.
thanks to anyone who can help.
Figure I might as well add my 2¢ to this thread too :wink:
I chose to mount the necessary heat producing load equalizer / resistor inside the car. After removing the interior panels to access the harness, you will discover there is a fairly large plenum area behind the carpet. Even better, there is a metal area it can be mounted where there is absolutely no chance it will come in contact with the carpet. I have had mine mounted and functioning in this location for the last 25,000 miles.
No problems, no evidence of heat by hand checking the carpet cover anywhere near the resistor location. Checked it once while unloading luggage after traveling 800 miles in summer with lights on, no evidence of elevated temp whatsoever. The downside is all the panel removal to gain access - mounting outside is down and dirty - both figuratively and literally :wink:
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Consulted a Bentley guide to remove panels. To remove the carpeted panel in the back, as per the Bentley, you are removing pretty much everything on top of it -- on a two door, you pull rear seats, front door sill trim, upper B-pillar trim, rear seat side trim, luggage cover side covers, trim around lower hatch opening - just to free the carpeted piece. I was running new wires for amber turns on LED tails at the same time, so all that was desirable for me anyway. Once you have access, it is straight forward electrical work.
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I was concerned about long term issues, wanted to be able to fall back to original lamps should the need arise. So I added a switch to add or remove the load at will. The switch is not required. Load is wired in parallel, the switch is in series with the load.
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After popping free two of the plastic tie down clips that hold the harness in place and removing some of the tape on the wire harness, I decide I better grab some kind of a 'before' picture. Once you are past the tail light junction, all that is left in this harness is the two conductors feeding the license plate lights, they run to the floor and through a grommet to the exterior location where Felix has mounted his resistor.
I chose to make the splice up high, the harness near the floor looks a bit delicate and I wanted to tie in between body mounting points. While I did not cut the wire, I cut the insulation, soldered in the new wire, heat shrunk ... < splice in progress >
... and taped it up after completing the splice ...
Mounted the resistor nearby in a blind pocket behind the carpet. the resistor can not come in direct contact with the carpet in this location. There is actually a fair amount of void area for air movement and heat dissipation.
There is actually a blind pocket below the carpet where my switch sits. Already two slits in the carpet piece where a flap can be easily lifted, I have no idea why the slits are originally there. The slits are barely visible inside the highlight rectangle. I placed the switch right behind that.
I am on my second set of LED bulbs since the install. I started out with LEDs from superbrightleds.com and while they worked OK for about 6,000 miles, eventually they began flickering. Never went out, just flickered all the time. So I switched to LEDs provided specifically for license plate use from
42 draft designs.
I know they say they are not for MK V, but I am assuming that relates to the lamp out sensing, which the resistor takes care of. So far, just under 20,000 miles and they continue to work great for me.
42 draft designs said:
14.5v 39mm Fuse Style LEDs
Size 39mm long x 11mm diameter
Available Colors White
LEDs per unit 4
Typical Applications VW license plate lights. These LEDs are built to handle 14.5
volts. Our standard 12v 39mm fuse style LEDs will NOT last
in VW license plate lights. These 14.5v versions are built to
handle the excess voltage and the heat.
Price $6.50 per LED
