Tighed1- On a completely different subject, I wished that I'd paid more attention to this forum a year ago. I spent 2 weeks in Sierra Vista in Aug. '08. Loved the area and weather and humidity (or lack of). we moved my daughter from here to there to be with her Army husband at Fort Huachuca. 1700+ miles in a u-haul towing her car @ 4 bucks a gallon.

 

Maybe we can get them stationed closer to you.
My brother is in charge of Army assignments. Just a thought!

 

We are a pretty slow bunch here, this solution has been known for three years on the benzworld forum. Pictures and everything.
We had better troll through that forum a bit better.
K40 relay circuit and associated - Benzworld.org - Mercedes-Benz Discussion Forum

 

Would not say that - look at the posts there they own '98 and '99+
took them 7 years - only 3 here

 

My point is that if we had looked at that sight 3 years ago we would have seen the solution.

 

You think that they could of trolled our site and then informed us!

 

I has posted a question on another Mystery No Start link, wondering where I could find replacement RCMs, then found this link last night. Pulled out the RCM, and wouldn't you know it, the EXACT pins were worn out on the board from my car, and in the same condition as the 'decent' board. Soldered the daylights out of the pins, placed the whole thing back in my car, and outside of a second of apparent hesitation when I started the car (I had disconnected the battery the night before since my husband was still convinced it was a faulty battery and not the RCM), my car has started beautifully.

Seems an almost too-simple repair job, really, and a potential money-maker for any stealership or mechanic who knows what to look for.

 

I guess they do not speak to the Chrysler bums.
Anyway, I took my RCM out and at first glance it looked OK. Looking at the joints with a magnifying glass told a whole different story, only this three showed poor soldering, one had a complete circle of a gap, not all the way through I would guess, just a nice halo.
Out with the Weller and a spot of resin cored solder on each and the job was done.
Thanks again tighed1, you did a good job.... again.
Of course if it fails to start one day I'll blame you.

 

Glad that others are taking the time to investigate the condition of their RCMs. I've had others PM me with the same results.

A quick look and everything looks fine. Closer inspection though reveals that the joints are going bad.

Still hoping that I can get an extra RCM so that if a forum member needs a replacement and can't have their car down (you know, those with only one XF to drive ) I would send the spare out and repair their bad RCM that they send me for the next member in need.

 

Smart man,That Tighed1. ... Squirrel Crusher

 

That is a great thought, Thanks alot. but they moved to Fort Bragg in june of this year. I think he is attatched to the 82nd Airborn. I think that he is getting deployed to Afganistan in Jan '10.

 

I reflowed ALL the connections on the Aero RCM. Great job tighed1 !

 

Great write up tighed1. Now, after the repair, I got a different problem, I can't shut off the engine. I was able to pull out the key and the car was still able to drive [put the car in reverse and pull out of drive way, drove it around the block and come back]. After pulling the neg/pos terminal of the battery and its still running [off of the alternator]. So what I had to do was pull the RCM which would shut it off. I'm assuming its my Ignition is the problem and not the RCM. I also did the "Me horny" mod also. I checked my soldering for that mod and making sure its not overlapping.

 

Start another thread with the title "Mystery No Stop"
Sorry I have no idea to help you.

 

Quote:

Originally Posted by Roxyfire

Great write up tighed1. Now, after the repair, I got a different problem, I can't shut off the engine. I was able to pull out the key and the car was still able to drive [put the car in reverse and pull out of drive way, drove it around the block and come back]. After pulling the neg/pos terminal of the battery and its still running [off of the alternator]. So what I had to do was pull the RCM which would shut it off. I'm assuming its my Ignition is the problem and not the RCM. I also did the "Me horny" mod also. I checked my soldering for that mod and making sure its not overlapping.

After you did the RCM Horny mod and installed the RCM and reconnected the battery, did you hear any relays clicking or fans running (with the key out of the car)?
If so you may not have cut your solder runs deep enough.

DON"T go spending $$$ on a new RCM if your car was fine before you modded. You can always jumper accross the cuts to make your car un-Horny. Or send it to me and I'll check it for ya.

DJ

 

Just finished doing the RCM resolder and horn of all time. Thanks for the great step by step info! Everything is ok except now my bas/esp light is on but that has happened before so no biggie as I followed a reset procedure that fixed that.

But now when I shut the car off I get 5 short beeps when I remove the key, Any ideas folks????

 

Haven't seen that one yet.
Post a picture (close up) of the RCM.

 

OK, going to pull it back out look it over and take some pics...amd then I'll get to the RCM lol

I was reading about the chime generator (section 8b of the crossfire service manual) but that only activates when lights left on or key in ingnition etc, and that chime is a lot louder, the 5 soft ones I get are like the one when the spoiler retracts all the way on manual mode.


Just a possibility, when cutting the green board to seperate the circuit points, I cut them a little deeper than appeared in your pic, Not way way deep thru the board but under a magnifying glass it looked like I was OK in seperating the copper flat wire. If there may be a spot within these cuts still touching, would that cause the beeps or could this be a residual effect from having the battery disconnected for aprox 1 hour? I haven't driven the car since the mod and am wondering if it just needs to relearn something

 

Not cutting the left cut will result in the symptoms that Roxyfire had, engine won't turn off ect. (BTW I mailed his RCM back Monday (7th) Priority Mail and he has yet to receive it. Any Mail persons out there wanta explain that???).
When I remove/reconnect the RCM I don't disconnect the battery (bad boy, bad boy). If you do that and while reconnecting you hear relays clicking, fans spinning, whatever, you didn't cut the runs deep enough.
One of the jumpers that are part of the Horny mod connects to the horn relay. If the ajoining cut isn't "cut" the connection is also made to other relays causing them to energize.
Remove RCM and cut deeper.
Or just send it to me!

 

Well it figures, cant seem to upload any pics to post. I pulled it and reinstalled it with the battery connected and nothing activated. looked at the cuts again and they are complete. Checked the solder points also OK. The beeping seems to be coming from right behind my defrost/heat dials?

Everything seems to work OK. BTW. If I start the car and then turn it off, when I turn the key left to the acc position and leave it there, the beeps dont happen. But if whenever I do turn it to off, it beeps after 1-2 seconds (5 short beeps) wether the key gets pulled out or left in/off