VY Tonner LED taillight conversion??

[savage1987]

The taillights on my parents' VY Tonner are useless. Cheap aftermarket ones.

Looking into the full LED taillight setups that you see on a lot of trucks around the place, the auto sparky says they're horrendously difficult to install, problems with cruise control, indicators etc etc. meaning they'd have to replace some relays along with other stuff.

Are they clueless or is this a valid issue?? Complicated?
Sam

[TMM]

It's true. If you replace your brake lights with LEDs you need to add "dummy loads" (simply some resistors of the right value in parallel with the lights) so that they draw the same amount of power/current as the old incandescent lights, otherwise the cruise control will act up.

For the indicators you need to change the flasher (for the lack of a technical term) otherwise the indicators will flash too fast.

I can't see how it's terribly difficult to install though?

The maths for the dummy loads isn't terribly difficult for someone familiar with electronics.
E.g. If you are replacing say a 20W globe with a 3W LED replacement you need a 17W dummy load:

Assuming Voltage = 12v
Voltage = Current*Resistance
Power = Voltage*Current

Work out required current for the load:
Current = Power/Voltage = 17W/12V = 1.42A

Work out the resistance needed:
Resistance = Voltage/Current = 12V/1.42A = 8.45ohms

It is easy to find a resistor around 8.45ohm, but not one that will handle 17Watts, so a few in parallel will need to be used. Two resistors in parallel will act like one big resistor with half the resistance and handle twice the load. So two 10Watt 17ohm resistors would work as one 20Watt 8.5ohm resistor, and that how you make your dummy load for each light . Jaycar stock 10W resistors suitable for the application.

[naf33n]

are you sure about the indicators, i just swapped my side indicators over to wm caprice LEDs, but to drive the car to the painter and back it didnt have any side indiactor at all and the front and rear still flashed at a normal rate, not the usual flashing really fast like i thought it would,

[BUT50]

TTM is correct I had issues with my tonner a couple of years ago but got it sorted it isnt that hard

[savage1987]

OK so there's a bit of playing around... Will have to try another auto elec as this one quoted over $250 in labour alone.