SLK 320 2001 Power problems, garage stumped

[JustineW]

hi
I have a 2001 320 6 cylinder SLK. I love it. Recently it has been playing up. After driving for about 20-25 miles the emergency lights go on, and the speedo hits 0, the car keeps driving but inevitably I'm driving at speed and so in gear 4 where it stays. I can only accelerate very slowly from a low speed, and the only way to re-start everything is to turn it off and back on. Then it will do it again in another 20 or so miles. After a while all the electrics go and the car wont start again without jumping it.

My usually brilliant garage cant find anything wrong with it. Computer not throwing any errors...

Has anyone had the same experience? Any ideas what it could be? The Aa guy thought it might be an intermittent alternator issue but thats not the case.

Help!

 

[V6Matty]

alternator or the reg pack isn't a silly idea, if the voltage drops to low the gearbox gets confused an goes into limp mode.

 

[grahamcol]

I guess it would throw an undervoltage code if the alternator's output was compromised ?

 

[television]

If a charging problem the car would just drive till battery flat, the car needs to go on STAR to see if something is recorded, I am wondering if the ignition switch is failing, the speedo going to zero looks like a speed sensor fault as this is also affecting the engine and gearbox.


Do get it on STAR and see if some code is there.

 

[JustineW]

Thanks. Have forwarded all your comments to my garage...