Styling Rear light unit upgrade

[puntodeltathema]

Hi folks. An Abarth 500 in my care has had the later post-2015 rear light units retrofitted (with separate arrangements made for reverse and fog lights). The car displays a parking lights warning whenever the headlight switch is operated (DRLs are fine). I think this is because the new light units only have 5w tail lights rather than the 10w bulbs of the earlier light units the car was originally fitted with. So the body computer is only seeing half the current it expects and throwing an error.

Does this chime with others who may have done this upgrade? One solution would be to wire in suitable resistors (given no 21/10w combination brake/tail bulb exists) - or is there a clever way to recode the body computer perhaps?

Thanks!

Nick

 

[A3jeroen]

Seen this on several fora. Only option is resistors to compensate the missing 5W.

gr J

 

[RedAbarthMTA]

Or as I have done just add another 5W bulb in series with the existing ones. I mounted mine in an easy to access box with holes to allow heat to escape or in fact anywhere you like, as long as you can get to them. Could be boot lights for example though would be on as long as you lights were on?

 

[puntodeltathema]

Thanks - yes was thinking about that. Did you mean in parallel though?

 

[RedAbarthMTA]

No, parallel halves the resistance, series doubles the resistance that the bulb check sees. 5W + 5W = 10W !
5W in parallel with 5W = 2.5W ( I know Watts are not strictly resistance but you get the idea. ) W = VxI , R=V/I