Ok, so lately (like the past year or so) I have encountered one issue after the other with this dam car. Very frustrating, to the point I'm thinking of selling!

Here's the latest head scratcher...

So last week I'm heading to get some dog food and pass a local automatic car wash which I've frequented many times. I get my wash and continue to the pet store. All is good and normal.

After getting dog food I return to my car, start her up and instantly my windshield washer fluid begins shooting all over the windshield with no end in sight. The wiper is not making passes while this is happening just constant fluid flow. So much for the $10 car wash. I then turn car off 2 more times and the same thing happens both times. Knowing I have a full tank of washer fluid I pop the hood and pull the fuse to end the madness. I drive home, investigate and find nothing. It keeps doing this for an hour or so and then seems to have fixed itself back to normal although I couldn't tell you why.

Next day I'm driving around 15 mph in downtown traffic and my wipers decide to randomly make 2 swipes and the horn honks at the same time neither of which I prompted to do so. This begins to happen more frequently over the past week now usually occurring every 10 mins of driving now. Its become so embarrassing that now have the fanfare fuse pulled so that im not randomly honking my horn at people for no reason.

I think the obvious conclusion is that this is some sort of electrical issue being that I started having these problems occur after going through the car wash (Or upon the first start after a wash).

I've spent hours researching and have come across some others experiencing similar issues but would like to know if anyone on here has had this problem or has any suggestions. Ive pulled error codes and none pertain to my problem.

Heres a list of problem areas others have pinpointed through google searches:

-SAM Module (Inspected contacts and looks fine)
-Drivers side window control module (Have not inspected)
-Some sort of electrical component under Passenger side floor carpet (Not inspected)
-Possibly a loose wire connection on back of Instrument Cluster or Climate control (Visually checked both and all wires seem to be intact) *Does anyone have a diagram that has all these wires and their functions labeled so I can pinpoint the wires that actually have something to do with the horn/wiper system in specific? -If so please share...


Any help is greatly appreciated, If I hadn't already dumped soo much money in this car and absolutely love her curves she would have been gone a long time ago. Its def a love/hate relationship and lately I've been thinking about cutting my losses.

I would speculate that the car wash got water somewhere it's not supposed to be (way to state the obvious ;-). The windshield washer fluid spraying and then resolving itself is likely from that water - after it dried out, the fluid stopped spraying.

The horn and the wipers may be due to corrosion induced by that water from the car wash. Is there a relay in common to both the horn and the wiper??

Of course, there is the possibility that the horn/wiper issue is totally unrelated to the car wash. Since the horn and wiper wiring are in your steering column, check the wiring to see if you have a short.

Sorry, not much help, but that's all I've got. Good luck!

Just a thought: all of the controls for the randomly activated systems run through the steering column. I guess I would look for a shorted wire in there somewhere as it seems to be a common denominator.

Well I inspected the SAM module and here is what I found:




So I cleaned it up with electrical parts cleaner aerosol and put it back together. My problem still persists unfortunately. Wipers, horn and left turn signal still randomly decide to turn themselves on for a quick second. Maybe the sam unit is toasted inside I really dont know...


Radaddict- I also would like to know if there is a common relay for these functions! Anybody know???

Jon- Should I just be looking for a worn through/cut wire?

I really dont see how water could have got to the SAM module connections considering its location. Makes me wonder if it is just toasted from age or hot/cold exteme weather conditions we have here in Kansas.

All that electronic hocus-pocus is beyond my powers of logical troubleshooting. I don't even know where the SAM is, but that looks like corrosion. I found this description of what it does from an S500 thread:

http://www.benzworld.org/forums/w220...ow-do-you.html

It seems logical that the SAM could be the issue based on that description, but there may be multiple SAM in the car. I'm not sure if you could replace one without messing up all the computer programming anyway.

So just for documentation purposes and possibly helping somebody with this same issue down the road I ended up swapping out my SAM module with a used one bought cheap off ebay.

Problem solved and I did not need to have it programmed at the dealership. It didnt even throw any errors upon first start up and I no longer have any of the issues mentioned above.

Thanks for the update, haven't experienced the entire issue (wiper sometimes randomly swipes when in auto position). Good to know you can swap the SAM without needing to go through the dealer.

I have exactly same problems. Thanks

I had replaced the battery, almost 2 weeks ago. Yesterday, it was raining really bad, today in the morning when I started the car, horn was trying to engage and wasn't completely engaging but kinda tooting. Hard to explain, wipers were very slowly moving automatically.

I disabled the relay for horn and wipers stopped too. Then I was driving on the freeway and SRS, cluster malfunction and 2 other malfunctions came on the ODO.

Question is, I think there is a short wire because of water/rain. How can I find it? Or is SAM toasted?

What is the location for SAM? Thanks for all the help.

Hello,
I know this post is old. Had the same problem. Bought a used SAM module from ebay for $45. Problem Solved

I am currently having a similar issue , although my issue is was getting a jump start and my buddy put the cables on backwards. Now every time i charge the battery my fluids start pumping and the alarm goes off. Am in the process of going through all the fuses and checking for burnt wires. I should be finished by tomorrow will post what I find.
Having another problem you apparently don't have. My key is in a locked position and won't turn. Just throwing that out there.