Avant Number plate LEDs - Now working !
Posted: Wed Jan 04, 2012 9:34 pm
Decided to attack the rear number plate lights again as was given a set of LED lights for Xmas. I don't know where they came from & they came in a generic box, but they were very ill-fitting & required the plates reversing so could engage the contacts - no surprise they flagged an error when not flickering...
I bought some 50W Resistors or "load ballasts" http://www.ebay.co.uk/itm/LED-Indicator ... 562ded09b6 with the original plan being to solder these to the "tangs" on the LEDs - I think 50W may have been overkill as is rated for a 21W indicator bulb rather than the 5W of the number plate bulbs but wanted to fix the problem first time...
When I looked inside the car again I realised there was not enough room to "tuck" the resistors away so I had to remove the tailgate trim, the idea being to get to the back of the contacts. As it turns out I gave up the fight with the rear trim - got all but 2 of the metal clips loose which whilst it wasn't ideal gave me enough room to identify the wires that feed the number plate lights/boot lock. A quick continuity test revealed the brown & grey wires (to the left of the 4 wires as you stand behind the car fed the numberplate lights (the share the same feed) so I spliced the resistor into the wires using some high quality scotchloks (if that doesn't sound too oxymoronic) & success no errors or flickering. I attached the resistor to the car with some double sided tape which I hope is sufficiently heat resistant & some cable ties for good measure as didn't fancy drilling the car - it gets quite warm but can easily touch it so I think will be OK - if it gets loose or the scotchloks fail then I will use some high-temp silicone & solder or crimp the wires know I know for sure it works. I only used one resistor & it worked fine so 2 are not needed which makes sense as 2 x 5 is still only 10 whereas my resistor is rated for 21W apparently.
Given we don't seem to have found any "error free" LEDs that actually are error free then I think some cheap non-error free festoon LED in the OEM cases & a resistor is the best solution - would also probably be a bit less bright which I think would also look a bit better too.
It was quite a bother so is not for those who are not familiar with trim removal & crimping & soldering but the wires themselves are easy enough to find & identify so the actual task itself is easy.
I bought some 50W Resistors or "load ballasts" http://www.ebay.co.uk/itm/LED-Indicator ... 562ded09b6 with the original plan being to solder these to the "tangs" on the LEDs - I think 50W may have been overkill as is rated for a 21W indicator bulb rather than the 5W of the number plate bulbs but wanted to fix the problem first time...
When I looked inside the car again I realised there was not enough room to "tuck" the resistors away so I had to remove the tailgate trim, the idea being to get to the back of the contacts. As it turns out I gave up the fight with the rear trim - got all but 2 of the metal clips loose which whilst it wasn't ideal gave me enough room to identify the wires that feed the number plate lights/boot lock. A quick continuity test revealed the brown & grey wires (to the left of the 4 wires as you stand behind the car fed the numberplate lights (the share the same feed) so I spliced the resistor into the wires using some high quality scotchloks (if that doesn't sound too oxymoronic) & success no errors or flickering. I attached the resistor to the car with some double sided tape which I hope is sufficiently heat resistant & some cable ties for good measure as didn't fancy drilling the car - it gets quite warm but can easily touch it so I think will be OK - if it gets loose or the scotchloks fail then I will use some high-temp silicone & solder or crimp the wires know I know for sure it works. I only used one resistor & it worked fine so 2 are not needed which makes sense as 2 x 5 is still only 10 whereas my resistor is rated for 21W apparently.
Given we don't seem to have found any "error free" LEDs that actually are error free then I think some cheap non-error free festoon LED in the OEM cases & a resistor is the best solution - would also probably be a bit less bright which I think would also look a bit better too.
It was quite a bother so is not for those who are not familiar with trim removal & crimping & soldering but the wires themselves are easy enough to find & identify so the actual task itself is easy.