A/C still not working after successful ignition lock switch install

[Mike Slack]

2003 C4S  with approx 46K mi.  Out of the blue the key got stuck and I could not remove it.  I was able to start the car fine, but also noticed that my A/C, HVAC blower, front headlights were also not working.  I replaced the switch with one made in Hamburg Germany that I bought from Advance Autoparts.  No problem installing (except for back muscle cramp!). Now ignition works perfectly and key removes and wheel locks normally... HOWEVER, A/C and blower are still dead.  I checked all related fuses and they are all fine.  I dug out the #4 relay from the secondary relay bank (under the Bose speakers behind the DRIVER's side) and am in the process of replacing that -more work that the ignition switch for sure.   I am pretty sure the ignition switch was original (had Audi symbol on it) but I got confused with the array of part numbers and different manufacturers out there.  Did I perhaps get the wrong switch; if so, why does it work fine as far as the key and lock mechnism?  Anyone been through this and have any suggestions.?  

[JFP in PA]

1 hour ago, Mike Slack said:

2003 C4S  with approx 46K mi.  Out of the blue the key got stuck and I could not remove it.  I was able to start the car fine, but also noticed that my A/C, HVAC blower, front headlights were also not working.  I replaced the switch with one made in Hamburg Germany that I bought from Advance Autoparts.  No problem installing (except for back muscle cramp!). Now ignition works perfectly and key removes and wheel locks normally... HOWEVER, A/C and blower are still dead.  I checked all related fuses and they are all fine.  I dug out the #4 relay from the secondary relay bank (under the Bose speakers behind the DRIVER's side) and am in the process of replacing that -more work that the ignition switch for sure.   I am pretty sure the ignition switch was original (had Audi symbol on it) but I got confused with the array of part numbers and different manufacturers out there.  Did I perhaps get the wrong switch; if so, why does it work fine as far as the key and lock mechnism?  Anyone been through this and have any suggestions.?  

 

Welcome to Renntech 

Unfortunately, you may be suffering from the dreaded "purchasing aftermarket parts" syndrome; these cars are notorious for not liking anything but the "real" parts.  As the OEM switch is not that expensive, I would suggest you are in for some more muscle cramps....... 🤥

[DBJoe996]

Let's start here.  Here is the correct OEM part number for models up to 2003

 

[DBJoe996]

I have read many threads on using an aftermarket switch and it not working out.  Many have tried the VW/Audi switch and it does what yours is doing.  For the cost and the pain of replacement, go OEM.

[Mike Slack]

Thanks for all of the helpful responses.  I am sure you all are right but I dissected the original switch (whith Audi logo) and couldn't find any recognizable differences between it and the replacement.  I guess there is some "magic" in those OEM parts that other legitimate German parts makers (i.e. Weyle) don't know about?   I took out my A/C relay (pain to get to!)  and it tested  working just fine.  Guess I am forced to change out the switch and see if this is an example of OEM parts replacement revenge?

 

 

[YellowJacketGS]

FWIW, I recently replaced mine - 2003 Carrera cab with this one - also OEM Audi /VW part - it was identical to the one I removed (which appeared to be the original unit with red paint on screws) down to every inscription. Works fine. Is there even one that says Porsche OEM?

Ignition Switch Genuine 4A0905849B 4A0 905 849 B 4A0-905-849-B 4A0.905.849.B | Pelican Parts

WWW.PELICANPARTS.COM

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Genuine Ignition Switch InStock Ships Today! $40.00. Call (888)280-7799. May Qualify For FREE SHIPPING. Parts# 4A0 905 849 B 4A0-905-849-B 4A0.905.849.B 4A0905849B. V8, S6, S4, RS6, Quattro, Passat, Coupe, Cabriolet, Boxster, Allroad, A8, A6, A4, 911, 90, 80, 5000, 200, 100.

[JFP in PA]

Buying parts from Pelican is perpetually a crap shoot; sometimes what they call an "OEM" part really isn't.  They have been doing this since I have been in the business, which is more years than I care to mention, and which is one of the reasons I never buy from them.

[YellowJacketGS]

Thanks for that information.

[Mike Slack]

So, to close the loop... I removed the replacement Meyle switch made in Hamburg, Germany part (it is inscribed with 100 905 000) which I bought at my local autoparts store because I could get it on Sunday.

As noted in my post, this part did fix the "Excalibur Key Syndrome" and the car would start just fine but many electrical components were not working (low beams/radio/HVAC).  I purchsed the so called "OEM" switch from Pelican Parts (Audi ring symbol; 4A0 905 849B) which looks identical to the broken one (Audi ring symbol; 4A0 905 849) but also looks externally identical to the Meyle one.  After installing this one from Pelican today, instantly, everything was back to normal and everything worked.  Externally, the parts look absolutely the same, but I guess there is some "secret sauce" inside that is not obvious to careful scrutiny.  I plan to dissect the Meyle one and compare it to my original (which I already dissected) to try to figure out what is so special about the Audi part?

In any case, a hearty Thank You! to all of you that recommended doing the Meyle German part swap for the Audi German part, even though it goes against my logical mechanical grain.   If I figure out the internal difference ("secret sauce") after the post-mortem , I will pass this information along. 

[JFP in PA]

Glad you got it sorted. 👍  Problems like this are more common than you might imagine 🤢

[Mike Slack]

Well, in case anyone is interested in mysteries and secret sauce, I did figure out why the Meyle part didn't work. It was a manufacturer defect in the part consisting of one of the spades was loose and pushed in about half way making it too short to make contact.  So, when I put it in and pushed the wire harness connector onto it, that loose spade pushed away and into the switch thus it could not make electrical contact with its corresponding connector in the harness   No secret sauce at all, just a poor job of manufacturing plain and simple (not made in China)!

[Mike Slack]

,,, by the way, my son and his eagle eyes is the one that figured this out!   Smart kid!