How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site. Ask follow up questions if you need to.
  • Go back-and-forth until satisfied
    Rate the answer you receive.
Ask Phillip H Your Own Question
Phillip H
Phillip H, ASE Certified Technician
Category: Mercedes
Satisfied Customers: 379
Experience:  Vehicle Technician at Richmond Motor Services
Type Your Mercedes Question Here...
Phillip H is online now

Merc R 170 230 slk. Driving along and vehicle cut out

Customer Question

Merc R 170 230 slk . Driving along and vehicle cut out completely. Stopped turned ignition key off and then restarted straight away, approx 1 mile later cut out again, this time would not restart. When ignition turned on all lights, vehicle external lights and fan etc all working however starter not operating. AA breakdown could not find fault, so recovered to my garage. Still cannot find fault, no codes recorded in ecu, have tried changing fuse box, relay box/unit, still no power to starter motor. Any pointers that you can help with. 1998 model forgot to put that in at the start of message.Many thanks. Kevin
JA: Is the power loss consistent, or does it fluctuate?
Customer: Before it cut out power was as usual, but nothing at all now.
JA: What is the model/year of your Mercedes?
Customer: SLK 230 compressor 1998 model R170
JA: Are you fixing your vehicle yourself? What have you tried so far?
Customer: Local garage and m changed relay myself. Check for fault codes none, changed fuse box, changed relay box, still no power to starter.
JA: Anything else you want the Mechanic to know before I connect you?
Customer: Could it be the ECU,
Submitted: 1 year ago.
Category: Mercedes
Expert:  Virtual-mod replied 1 year ago.

I've been working hard to find a Professional to assist you with your question, but sometimes finding the right Professional can take a little longer than expected.

I wonder whether you're ok with continuing to wait for an answer. If you are, please let me know and I will continue my search. If not, feel free to let me know and I will cancel this question for you.

Thank you!
Expert:  Phillip H replied 1 year ago.


This could be a tricky one to find. I have checked for a wiring diagram however Merc being Merc don't release anything for Aftermarket use!

Obviously with their being no codes you have pretty much eliminated any electronic faults i.e sensors etc.

Without a diagram it will be back to basics and find out where the trigger wire that energises the starter motor solenoid via the ignition switch goes! It could be the ignition switch itself has a burnt out contact in the the start position.

If this isn't the case it will be trace the wiring. I'm not sure about Mercs but other vehicles I know of have a habit of routing the wiring through other things such as Junction Boxes (Fuse Boxes) which in effect act as a bridge between two separate looms on the vehicle.

I will assume that the garage you have taken it too have put their own live wire to the Trigger wire terminal on the starter in order to confirm that it isn't just the starter that is a fault and I will asume that while the key is help in the crank position they have checked for feed at the trigger wire!

If the faut lies in a broken wire within the loom it is often easier to bypass the broken bit and run your own wire!

I don't think I can offer any further help other than good luck in finding the fault.

Hope the information I have provided helps a little in tracing the problem.