dreadlockdw
Senior Member
- Joined
- Feb 16, 2014
- Messages
- 378
- Reaction score
- 40
- Location
- Wakefield
- Your Mercedes
- clk 500 cabriolet 2005; E280 1993
Seeking some advice and help please.
Stepson has a 2015 CLA 45 and it gets plenty of 200 mile journeys and has been fine for several years until the other day when it wouldn't start (dash and lights working).
It jump-started no problem (using the correct connection points); did around 100 miles; restarted after a fuel fill up and did a further 100 miles, prior to being parked up overnight at my place.
There are no apparent obvious battery drain things going on - internal power socket unoccupied and interior lights extinguishing correctly...
Following morning same symptoms as before - dash lit up but no start. I jump-started it using a separate battery, and it drove fine, with no warnings on the dash, but it wouldn't restart, and on further jump start now has engine warning light on.
We then fitted a correct brand new AGM main battery and car is running and starting ok but still with engine warning light on.
It remains to be seen whether a failing/faulty battery was the sole cause of the problem.
I connected my CTEK 5 to the old AGM battery and set it to do a full recon/recharge which appears to have completed through to the green light at the end of the cycle. My understanding is it wouldn't get this far if the battery was completely gone?
My questions are:
1. I believe the CLA will show a dash warning if the alternator isn't working correctly? Otherwise is there any way to check alternator without multimeter? On my CLK for instance one can access a direct voltage reading on the dash, which reads 12v plus with ignition on engine off and then goes to 14v plus when the engine is started, indicating charging ok.
2. If everything is ok will the engine check light extinguish itself in due course or will it have to go on Star at some expense to have codes read/reset?
3. Is there anything else we can do or consider?
Stepson has a 2015 CLA 45 and it gets plenty of 200 mile journeys and has been fine for several years until the other day when it wouldn't start (dash and lights working).
It jump-started no problem (using the correct connection points); did around 100 miles; restarted after a fuel fill up and did a further 100 miles, prior to being parked up overnight at my place.
There are no apparent obvious battery drain things going on - internal power socket unoccupied and interior lights extinguishing correctly...
Following morning same symptoms as before - dash lit up but no start. I jump-started it using a separate battery, and it drove fine, with no warnings on the dash, but it wouldn't restart, and on further jump start now has engine warning light on.
We then fitted a correct brand new AGM main battery and car is running and starting ok but still with engine warning light on.
It remains to be seen whether a failing/faulty battery was the sole cause of the problem.
I connected my CTEK 5 to the old AGM battery and set it to do a full recon/recharge which appears to have completed through to the green light at the end of the cycle. My understanding is it wouldn't get this far if the battery was completely gone?
My questions are:
1. I believe the CLA will show a dash warning if the alternator isn't working correctly? Otherwise is there any way to check alternator without multimeter? On my CLK for instance one can access a direct voltage reading on the dash, which reads 12v plus with ignition on engine off and then goes to 14v plus when the engine is started, indicating charging ok.
2. If everything is ok will the engine check light extinguish itself in due course or will it have to go on Star at some expense to have codes read/reset?
3. Is there anything else we can do or consider?
