2 replies to this topic

[TAYLOR72]

Hi.

 

I am having problems with the hazard warning flashes. I originally thought it was the switch so replaced this and the issue is still there - the switch when pushed will light all of the indicators but not flash

 

I have now I think norrowed it down to this variable load signal flasher which seems to be working intermittently. Any ideas how to fix or is it just a new one needed. I had a quick look couldn’t see anything like it on the Internet

 

 

[NLinPEN]

Are the bulbs used conventional incandescent bulbs, or have they been replaced with LEDs? The current consumption of these LEDs is less.

[alpder]

AFAIK there are two basic formats of flasher unit: 2-pin and 3-pin.

 

Each will be rated with a maximum (and sometimes a minimum) wattage. If used for hazards with normal bulbs then needs to be rated 4x21W (+ 2x5W if you have repeaters.)

 

The internal tech of the units will vary. Most detect when the load drops to less than 2x21W, and then they flash double-speed, as a warning to the driver that one bulb has failed. They don't work with most LED bulbs because the LEDs often don't load-up the flasher enough - which they interpret as a bulb failure.

 

It's quite common now to retro-fit "LED-compatible" flashers when a replacement is required. These can work even if the bulbs draw very low currents - as most LEDs do. Downside is that bulb-fail detection and double-speed flashing is disabled. If that was a required safety feature of the car then our increasingly aggressively payout-dodging insurers might play on that in event of an accident caused by, say, you thinking you're indicating but the approaching car's dashcam showing only a dead bulb/LED on your car.

 

Worth bearing in mind that since roughly 1970 (don't know the exact date - but someone here surely does) UK cars require E-marked bulbs... but last time I looked there are no E-marked replacement LEDs for filament bulbs. So, somewhat weirdly, you can legally fit LED bulbs to some 60's cars, but not to more recent cars. Though good luck when you get into a 'discussion' with a roadside VOSA officer about it. (Edit: I see that Osram are now making street-legal LED bulbs. Though there is a footnote to the effect "Only legal in some countries".)

Edited by alpder, Yesterday, 09:04 PM.