Just bought my first Crossfire. Everything was great for about 2 hrs. Now it still runs fine but speedometer and brake lights not working and all the dash warning lights are on. I cleaned up all grounds. I looked at the rcm at the solder joints look ok and all relays appear good. No dark or burnt contacts. Should I order a new rcm? Thanks for any insight.

 

Try this, disconnect the negative lead from the battery and let it sit for a few minutes. If you have a voltage tester check the battery voltage.
If the battery is old or the voltage is low, it will cause all kinds of weird things to happen.
Reconnect the negative cable and see if the trouble is still there. If it is, it could be the RCM. Even though it looks good it may not be.
Grab a spare off of amazon and send your original out to @tighed1

 

RCM. Your RCM's power output to the brake controller has failed. Check all fuses on the RCM (I am too tired to go grab the manual to tell you which fuse it is, but one of them on the RCM powers the brake controller).
IF all fuses are good, then either the Traction Control relay is bad or the soldered connections from the relay to the connector pins are fractured somewhere.

I would order a new RCM, then send your bad one to DJ in Arizona. FOr abotu $65 he will replace the relays and reflow solder. You will then have a spare to carry around with you.

Go to the internet, search for "2003 Mercedes SLK320 Relay Control Module" and order one. Or, search for the Crossfire and either never find one or find one and pay too much for it - they are the same part.


This is not an intro thread, this is a tech help request - moved to appropriate forum.

 

Thank you for your help. I checked voltage 12.32. Even checked it to body ground and motor. I will order a new rcm today

 

Thank you for your help. All fuses good. I will order a new rcm today

 

 

above is kinda a high price somewhere around 100 maybe on ebay.
but look up mercedes k40 and then look up chry crossfire rcm. the limited and the srt6 use the same rcm.
if you know someone near you that would let you swap rcm's to check it.,but we know it is the rcm
so you could just get a new one and then as pizzaguy said,,

,and i quote "I would order a new RCM, then send your bad one to DJ in Arizona
FOr abotu $65 he will replace the relays and reflow solder. You will then have a spare to carry around with you."

 

Thanks, I was afraid to buy the cheapest. I read a few reviews of them being defective right out of the box.