Flasher unit DIY repair (part 8Z0 941 509 B)

[Dev]

Hi all,

my flasher unit packed up this week, just when I need new roll bar drop links, a new cam belt and an MOT. Not wanting to spend any more, I decided to try and fix it.

My A2 is an X-reg TDi, early 2001. The flasher is mounted behind the storage compartment in the central dash console. The compartment is held in with a couple of clips on either side. Stick both hands into the compartment, spread them out and pull straight back, wiggling from side to side and the compartment pops out.

I found it easier to reach the flasher unit if I also took out the radio and ashtray. I didn't need to disturb the heater/air control panel.

The ashtray is held in with a couple of torx headed screws which are uncovered when the storage compartment is removed. When taking it out there's a connector to disconnect at the back.

The flasher unit is held in a cradle with its connector on the end at the left. The cable to the connector is held captive by a cable tie underneath and to the right, which I had to released before the cable would have enough slack to disconnect the flasher. The connector has a couple of retention clips which are fairly obvious. Squeeze them in and wiggle the connector out.

The flasher unit is locked into its cradle by a couple of spring clips. Squeeze them together and slide the flasher unit out towards the right.

There are a couple of clips holding the flasher's cover on to the connector, just by the free ends of the spring clips. Gently prize them open with a penknife and the printed circuit board slides out.

There are two small open frame relays just next to the connector, one for the hazard lights and one for the indicators. You can tell them apart by looking at the contacts: the hazard relay has two and the indicator relay only one.

The problem with my unit was degradation of the indicator relay contacts. It looks like a "cost-optimized" design to me: the relay has tiny contacts which aren't really up to the job.

The choice of relays my local electronics store (Maplin's) was fairly limited, but I found a flattish sealed relay with a 12 V coil and 16 A contacts for about £1.80. I'd have preferred a 20 A contact rating but I needed to get the car back together quickly.

It's then just a matter of removing the old relay, selecting an orientation for the new relay to fit it in the package with no risk of shorts, soldering connections the relay with suitable gauge wire (I used bell wire for the coil and 1 mm solid copper wire for the contacts), and restraining the relay with a couple of self-adhesive foam pads to prevent fatigue on the wires.

It works a treat - the only change is in the sound the relay makes. Not bad, just different. It's easy to run a quick test, since the flasher connector will hang out into the ashtray space. To reassemble everything, just reverse the dissassembly sequence.

If you want to try this yourself, be careful: there are lots of sharp edges in the centre console innards. Many skin cells died to bring you this information.

The flasher circuit uses the U6043B IC, made by Atmel etc.

Cheers,

Dev

[spike]

Hi Dev

Out of interest, did you price the Audi flasher unit. I've heard the Dealer charges up to £200 to replace one and wondered what the part cost and how much was for labour.

Cheers Spike

[Silent1]

Does the new relay not affect the speed at which the indicators flash or is that governed by something else as well?

Having also take many sections of the dash apart i can attest to the car being carnivorous!

[Dev]

Hi Spike,

I didn't get a price for the Audi unit. I'm sure it would be another case of "quote me miserable".

Dev

[Dev]

Hi Omitchell,

the flashing frequency is determined by a resistor-capacitor (commonly RC) timing circuit used with the U6043B integrated circuit. None of these components are disturbed when replacing the relay, so the frequency is just the same as before.

Cheers,

Dev

[toby1]

The part number quoted at the beginning of this thread, from an Audi dealer is retail £20.59 + VAT = £24.19.
If you're interested the cost price (dealer nett) is £14.82 + VAT = £17.41.

[Dev]

Thanks Toby,

not quite as outrageous as I feared, but with fitting added on top of that it looks like I've saved quite a bit.

[crb1011]

I had my flasher unit replaced by a VW dealership under warranty and I asked how much it would have cost if not covered. I was told around £150 including part and labour and dreaed VAT. As my warranty cost me £300 then I am halfway there in getting my moneys worht.

[unipower]

I've just had the same problem on my Aug '02 build 1.6FSi. Hazards & bulbs OK, LH & RH indicators don't work (1 click & single flash on dashboard). Car does not have climate control. I've tried the method you describe but cannot remove the storage compartment. Just to confirm the arrangement in the centre console:- Cup holders at top, radio cassette, heater controls, storage compartment, then ashtray at the bottom.
Storage compartment is fully lined with carpet material - no obvious catches.
Any ideas appreciated!

[crb1011]

sounds like a classic sympton of flasher unit relay gone. The hazard indicators will work as you are pulling more current through the relay when operating 6 indicator bulbs (3 on the RH and 3 on the LH). When using the indicators normally you are pulling less current (only using 3 bulbs at a time). Had mine changed by VW dealer under warranty. Maybe you could do it yourself if you have the knack. I can just about check the oil and water on my A2 never been good at car mechanics