Mustard Relay is Amazing

[montelatici]

Ok, the only suggestion I am making is that before you change bulbs, tear open your cluster etc., make sure you "Mustard Relay" is operational. I recently lost my dashboard back lighting (the orange to see the speedo, tach, gauges etc.). I was about to tear out the dimmer then remove the cluster. In the meantime I noticed I lost my rear lights and one fog light. I did some soldering to see if I could do the mustard relay repair by flowing some solder over the joints. Reinstalled the relay, no luck. So I removed the relay and voila, the dash lit up and the tail lights came on as well as all the side (parking lights). one of which, the right rear, had not worked before. Right fog lamp was still out however. I reinstalled the relay and every thing continued to work, but I am sure the relay will cause future failures. So, it is my opinion that this silly little relay affects quite a few circuits. I have ordered an Audi equivalent and will see what it does before I continue to change bulbs or worry about my dash back lighting.

[CroughtonE32]

I believe if you read everything posted on the E32 forum about the infamous "Mustard Relay" you'll find that some folks will swear that replacing it not only fixes goofy lighting problems both outside and inside our cars..............but has also reversed drought conditions slowed down hurricanes stopped tornadoes dead in their tracks as well as healed a few disintegrating marriages. Not sure why you're buying one from Audi but BavAuto has a new one for about 115.00.


Somewhere here Shogun has a thread showing you how to fix it yourself. I looked through my Shogun fixes but can't find it. I'm sure it's on it's way. I remember studying it. Lots of pictures and instructions.

[montelatici]

I read the fix, I flowed all the joints with solder and it did not change anything, perhaps the relays themselves are shot. The Audi relay from Hella (not Audi but the Audi forum says it's the same) costs $8.95, so I thought I'd give it a try.

[shogun]

The repair is on my site, but not always resoldering helps. Some pics http://www.bimmerboard.com/members/take/masterd.jpg

Audi/VW relay: Tail light / park light messages VW/Audi 447959875
resoldering http://bmwe32.masscom.net/sean750/mu...stardRelay.htm part number 61 31 1 378 052

I posted this once in 2008/9 but have never tried on my car, hope it works: http://forums.bimmerforums.com/forum...-Mustard-Relay

VW | Audi | Seat | Skoda have the same relay, # 447959875, but for another purpose. They call it Fensterhebersteuergerät,= electric window control module (and for electric sunroof), might be cheaper.

Found this: quote
Found another fix to the Mustard Relay. I have a 1985 Audi 5000 cd turbo that I am going to scrap and I got thinking they are both German there must be some parts the same so I thought I would take what I want off before I scrap it and voila,I found the mustard relay.That lights going out happened to me a few times and it is scary.

UPDATE! MUSTARD RELAY NUMBERS.Sorry guys I took so long but tried to take pics, but my camera is junk,but here are the numbers. 447 959 875, made by HELLA. It is abt 3/8S higher but still fits and I think my lights are brighter and haven't gone out since! Exactly the same prongs.

unquote

BTW: there are 2 kinds of mustard relays. One has 'mustard' inside = electronics which can be resoldered such as relays, see here my one under repair http://www.bimmerboard.com/forums/posts/249600/
And there is a mustard relay without 'mustard' inside and it has only some metal connections inside. All older E32 have mustard relays with mustard, later on some models such as the 740 this part in charge for side lights/parking lights moved into the LKM, and from then on it was without mustard.
with 'mustard':
Lighting Relay; Daylight Driving/Taillight; 7 Prong Connector 61311378052 list price $57.91
the other one has 5 prongs
61311378525 called connection plug low beam and costs only a few $

Relais VW Audi Nr 447959875, but for another purpose. They call it Fensterhebersteuergerät = electric window control module (and for electric sunroof), might be cheaper.
Also used in Seat and Skoda, just fould a picture so you can compare
http://www.ebay.com/itm/VW-Audi-Seat...-/271261648988

AUDI 447959875 control unit can be found in the folowing cars http://www.partsbase.org/parts/aud-447959875/

[montelatici]

Just to let people know, I bought a new Audi p/n 447959875 for 25 bucks. Replaced the mustard relay and everything works now. I reflowed the solder on the old relay but I wasn't successful. I am not a great solderer but I do repair electronic (classic audio) equipment as a hobby, so I am not a terrible solderer.

[Ron750il]

I successfully was able to re-solder the relay by reflowing

So after Shoguns technical write up and Derek Ks confirmation I went ahead and gave it a go. I decided to just fix the mustard relay because I was only having issues with the driving lights and tail lights. Its approximately $40 for the relay as opposed to .25 cents to repair. I basically just reflowed the solder using flux and lead solder not silver. Pictures below before, tools used, progress and completed relay.









- - - Updated - - -

The lights still work after the fix and I will see over the next few days if the repair fixed the "tail light out" or "parking light out" error.

[montelatici]

Everyone should try reflowing first if they want to save money, but even Shogun, as I recall, had an unsuccessful attempt at reflowing. At 25 bucks, the Audi relay may cost less than your time.

[Derek K]

I had the same problem a month or so ago. Tried to re-solder the joints (with new solder) but it still didn't work right (I solder very seldom). I took it to a friend, who works with electronics daily, and he removed the old solder with a solder sucker then flowed new solder onto the joints. My mustard relay has worked perfectly ever since.

[tasyurek]

Just to let people know, I bought a new Audi p/n 447959875 for 25 bucks.

Where did you buy it from?

Thanks.

[cnorto20]

Where did you buy it from?

Thanks.

Also wondering if anyone can tell me where to get the equivalent Audi part from online? I can't seem to find it listed anywhere, thanks!

[shogun]

Just google search for Audi 447959875
AUDI VW SEAT SKODA RELAY 447959875