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

Dev

A2OC Donor
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

Well-Known Member
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

Member
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

A2OC Donor
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

A2OC Donor
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

Member
part price

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

A2OC Donor
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

Member
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

Member
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

Member
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
 

Skipton01

Well-Known Member
To remove the storage compartment, all you need to do is insert both hands into the space, spread them outwards and then press and pull at the same time.

It is remarkable how stiff it can be, but there are only two clips holding the unit in place.

Make sure that the ashtray is in the out position before you start, otherwise it will break.

The flasher relay is then easily accessed - it's a small black box at the rear of the storage compartment, held in place by a quite fragile plastic strip.

See this thread: http://www.a2oc.net/forum/showthread.php?t=3809

It's got a few photos showing the tray removed.
 

unipower

Member
Thanks for the tips - success!
I followed Dev's route and with the great comprehensive instructions, fitted the Maplin relay (original indicator relay confirmed with burnt/damaged contacts).
A few points I found, based on the instructions in the first post:-
I first removed the fascia from the storage compartment, so it was then possible to see the spring clips on either side - these can be levered back with a thin blade.
I didn't need to remove the radio.
If the flasher unit is moved to the right, it is then possible to pull off the connector without releasing the cable tie mentioned.
 

lowedb

Member
Thanks for the help, and a hint from me

Thanks for the help, after a swift search, found your page, and fixed my problem in minutes.

I pulled the unit apart and sure enough could see the problem contacts on the relay. As I didn't have one to hand, I tried cleaning as a temporary fix, and was surprised this made no difference. So I got the relay under a magnifier and had a good look. The problem is not dirt (although the contacts were dirty at first) but wear. The contacts have worn away so much that when the contact carrier touched the pole of the magnet, it wasn't actually touching the two contacts together. So a small application of a screwdriver behind the fixed contact made the gap smaller, and sure enough it works fine again.

Even if this only lasts a few weeks, it gives me time to source a replacement relay rather than shelling out for the complete unit.

Incidentally, it looks like an almost identical part is used in the Skoda octavia. Maybe the part is cheaper from them?
 

vkx245l

A2OC Donor
8Z0 941 509B price update

Just to say thanks to everyone who contributes on here. Passing through Scotland at the weekend and the indicators start to pack up. As we had to drive back to Exeter thought I'd pop into the local stealers, Camerons of Perth, and buy a new unit. Quick search of the forum first to check part number and "how to" info. Parts guy impressed with the part number, 10 mins to fit and on our way.
Only problems were that the righthand clip holding in the storage tray got caught and broke but seems to stay in ok with one although I will try and source a new one - oh yeh and the price £25.59 +VAT (= 30.07).

Thanks again

Jonathan
 

baard

Member
To get access to the relay I have to remove the climatronic unit because of dobbeldin stereo. I havee successfully removed the stereounit, but cant find the screws that holds the climaunit back? How to remove the climatronic unit?
 

Skipton01

Well-Known Member
Baard, I've replied to your PM, but just to clarify, there are no screws, just clips. To remove, push from the back, quite firmly and the panel will come out.

Cheers,

Mike
 

whuy

Member
Try as I might, and can't get the storage compartment out, or even the fascia for that matter.. can't even get close, it's such a tight fit. And it's getting urgent, as the indicators hardly work at all any more.. To get the fascia out, do you have to worm a screwdriver behind it somewhere or what? I'm afraid I'll break it before I manage to dislodge it. Argh I guess I'll leave it to the dealer's..
 

A2driver

Member
Thanks to Dev I was able to change my indicator unit on my wife's A2. Like he said plenty of nasty sharp bits. I took the old unit apart but I struggled to find a suitable relay (size + amps) from RS and Maplin -as time was pressing 'when are you going to fix my car?' I bought a new unit from Audi for 24 inc.
Here's some pictures.

This is where the bugg£r is situated with the tray removed.




Relay for indicators is pictured on the left/bottom, hazards on right top



 
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A2driver

Member
To get the tray out I kind of wedged both hands in and wiggled L+R whilst pulling backwards -quite a bit of force necessary
 
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