LED indicators

[jimbo88b]

Hi, i've fitted some LED front indicator units, but now the indicators flash too quickly as if a bulb has blown. I'm guessing this is due to the lack of resistance from the bulb which has been removed. Can i get round this by soldering a resistor in line and does any one know what size i would need to use, or am i completely wrong? Any help greatly appreciated, thanks, James.

[flybynite]

I think you have nailed it on the head but to know the answer you would need to measure the current the LED uses and apply ohms law

[Brianmoooore]

You don't need to add any resistance in series. You need to add it in parallel to the LEDs, to increase the current draw. The resistor would need to be about 3.5 ohms, and will dissipate about 50W instantaneously, so will get very hot.
A cheap and readily available source of suitable resistors is a couple of 12volt 21W lamps, which will conveniently fit straight into the lampholders BMW provided.
There is a legal requirement for you to have a lamp failure warning system for the indicators, and this is what the standard flasher module provides.

[flybynite]

A cheap and readily available source of suitable resistors is a couple of 12volt 21W lamps, which will conveniently fit straight into the lampholders BMW provided.

I'm guessing this is due to the lack of resistance from the bulb which has been removed. Can i get round this by soldering a resistor in line

Sorry I did not read your post well enough when I said

I think you have nailed it on the Head

But OHMS LAW will still see you good

You can get bulbs with this built in ‘canbus friendly’ or ‘error free’ or buy resistors with heatsinks ready made Lots of proper things made to do a bodge job

People use these on modern cars when they cannot be bothered to get the car coded correctly for LED lamps.

Thankfully the E30 does not have a canbus (as standard) but the principle is the same

The only problem is you won’t know your bulb has blown (quite a common thing with cheap LED bulbs) you will only know if your resistor blows. And if you put a normal bulb back in temporarily (because the LED has blown for the 10th time) it may draw too much current and blow your fuse.

The best way may be to get a proper LED friendly flasher unit like these

https://www.auto-lighting.co.uk/product ... JL-02.html

I have not tried one, let alone in an E30 but see no reason it would not work if you check the pins are correct. (I think the E30 is CF13)

Lots of information already out there about this

[martauto]

A cheap and readily available source of suitable resistors is a couple of 12volt 21W lamps, which will conveniently fit straight into the lampholders BMW provided.

Mart.