Rear LEDs

My 05 TF passed the first MOT in my ownership but not after some failures:
- emissions (the engine was cold)
- both rear indicators too white
- handbrake travel

The garage who I give it to discussed with the tester and it passed. But that made me get a couple of (Philips) orange LED indicators and put them in.
The bad news is that it upset the circuit and they flash at double rate. Back to incandescents for the moment.

Has anyone changed to LEDs and what brand/type did you use?

The flash rate of incandescent indicator bulbs is determined by the resistance of the bulbs..... so the higher the resistance the slower the rate and the opposite lower the resistance the faster they flash, when LED bulbs are fitted to a system designed for incandescent bulbs they flash too fast as LED bulbs have a much lower resistance which is inherent in the nature of LEDs, to use LEDs in these older designs a resistor of the correct value must be used to add resistance to the circuit.

You’ll need a couple of fat resistors in parallel with the lamps, I can’t remember the rating but I’ll check later.
It’s brew time & if you think I’m going to do Ohms law over a cup of Earl Grey your one off.
There not a lot of ohms but are quite high wattage.
M

You can swap the standard indicator flasher unit for a modern non current dependant one. I did this recently on my MGB project car as I was introducing LEDs. Cheap as chips to buy. Where the indicator flasher relay is located on an F / TF though I'm not sure. If in doubt as Airportable says just buy led indicator bulbs that have parallel resistors built in, they are available.

The LED flasher unit isn't compatible with our cars, ours use a three pin unit (YWT10003), where as the LED flasher units I've seen are two pole. The load resistors work out to be 5 to 10 ohms & need to be around 25 watt +.
Looking on everyone's favourite general store (Ebay) there are any number listed & they are rated as 6ohms @ 50watt & about £6-00. You need I per lamp, (if you want to know why you can't use one per side give me a shout). I searched for LED resistors & was straight in.
M

Just look for the word CANBUS on the led indicator bulbs. I've seen a set of 4 on ebay for a tenner.

I think I’m correct in saying that the CANBUS compatibility LED lamps have an electronic load built in & that spoofs our cars into thinking that the load is comparable with an incandescent designed system.
The price range of LED for car applications is vast & you really do get what you pay for. I’ve tested a good number & if anyone wants any free samples of ones I’ve considered second best just pop around, but do bring a carrier bag.
One problem with LEDs is also their strength & that’s their low current drain; some draw so little that that small amount won’t draw enough to overcome the contact resistance of a poor quality fitting.
The contacts on the rear light clusters on our cars are a mild steel pressing which is then plated (possibly some tin alloy) & the slightest bit of corrosion will create a high resistance. This resistance will be sufficient to attenuate the light output to virtually zero. An original lamp, drawing more current would “overcome” that resistance.
The near side rear indicator on my car dims appreciably & it requires the contacts cleaning, I have to do this from time to time even though I use a spot of Electrolube on the contacts. Why just the near side, I’ve no idea?
One last thought: the lamp fitting has two connections & it’s usually the steel pressed plate that causes the problem, the positive contact, which looks like it could be some brass alloy gets kacked up. This, I think is deposition of contact material from the lamp positive. It’s always good practice to give that a clean when you are in there, an old fashioned ink rubber is very useful for this.
M

Can I amend something I wrote earlier. I stated that the LED flasher unit was only available in a two pin package, I have now found a three pin equivalent, whether it is pin compatible to ours I don't know. They are around £7-00 so a bit too much to buy as an experiment, especially as I've had my wrists slapped for spending too much on my various projects (& there are quite a number!).
If you put this into Ebay you should turn up the device.
"12V 3 Pin Adjustable LED Flasher Relay Unit For Car Turn Signal Light Indicator".
M
Final edit; the three pin LED flasher module looks like its pin compatible. When I'm back from holiday I'll order one to see & if it works it will negate the use of resistors.

12 V 3 Pin LED Flasher Relay Unit Adjustable For Car Turn Signal Light Indicator Buy It Now

As usual, excellent info. Much appreciated.
For £6, I have the resistors on order from the Bay. Surprised to see what large heat sinks are used on them.

Will fit and report.

Those are the exact 3 wire flasher relays ive used on my MGB Mike. That car had separate old flasher units for indicators and hazards, one rated for 2 bulbs and the other for 4. As one had failed and the other was getting unreliable I replaced both with these new types.  They just needed an earth wire to the 3rd terminal then were plug and play. They have the advantage I can now use any combination of LED and incandescent bulbs at all for the indicators on that car.. 

Thank you, it’s not as easy for those who are past their optimum to keep up with new trends. I usually start by trawling up old ides & then massaging them into something that fulfils the modern Idiom.
I grew up with with cars with crank handles & had I been faced with the first transverse engine to adapt, I would have worked a hole for the handle in the side of the car.
And if you believe that . . . . . .
Back to the flasher unit. A bit of searching turned up a device which was listed at just over £4 with offers invited. I never miss these offers & ended up with one the slow boat from China, for £3-50. I recon that’ll do as a start.
The relay is on the fuse board, under the steering wheel, at the top left hand corner, at least on my f
There is a diagram out there which shows the cigarette lighter relay as the flasher. This dumb sod ordered that relay in error after an indicator fail in the early days of ownership.
M

Resistors fitted.
Superglued them to the back of the cluster covers, near the cover vents.
Thanks for the advice.

The Philips LEDs are much brighter, especially side view.