2003 SL500 not starting

[chalks]

Hi

My SL500 had been stood doing nothing for a year. Put new batteries on it and jobs a goodun, started up. Fast forward a week, and it won't start.

Everything sounds like it should, turn the key and get a single crank noise then nothing.

I disconnected the batteries today and reconnected them tonight, but still having the same problem.

Locks and unlocks fine, so don't think it will be the immobiliser?

Maybe the starter motor but seems strange it started straight away last week?

Any help appreciated!

Cheers

 

[MikeInWimbledon]

What's happening to the general electrics?

Lights OK, Comand OK, dashboard lights? Is roof operating OK. (Don't do the whole roof thing - just in case - just see if it starts to operate.)[YOUTUBE HD][/YOUTUBE HD]

Any "Convenience functions only" messages on the dash?

If they're all fine - then we're off to the ignition circuitry / isolation.

 

[chalks]

Lights OK, Comand OK, dashboard lights? Is roof operating OK. (Don't do the whole roof thing - just in case - just see if it starts to operate.)[YOUTUBE HD][/YOUTUBE HD]

Any "Convenience functions only" messages on the dash?

If they're all fine - then we're off to the ignition circuitry / isolation.

Hi

Left hand dial has battery pic, right hand has visit workshop - both in red. They were there when it started before though so don't know if it's related.

Just opened the door to check the lights (left it unlocked) and when the door was opened the alarm went off, so back wondering if it could be immobiliser related

 

[chalks]

Anyone got any ideas?

 

[richard]

Have you got the correct batteries ? Did you get them from Merc or somewhere else ? You shouldn't have the battery error message after putting the new (correct) batteries in ..

R

 

[grober]

Sounds as if you may have a faulty alarm sounder unit. They contain their own backup batteries and eventually these go causing a variety of weird faults/current drains . The sounder unit is to be found under the drivers side ? wheel arch liner and susceptible to water corrosion damage. Replacements used to be about £100 from MB?
https://mbworld.org/forums/sl-class...goes-off-no-reason-kills-battery-fix-diy.html

 

[oldguy57]

Possible alternator fault? Our SL which gets irregular use displayed the same symptoms early this year. Put on Star and replaced alternator - been fine since. Can you jump start and check alternator output?

 

[Ted]

What voltage do you have across the main battery terminals, both before cranking and during cranking?
That will help to give an informed answer.

 

[Monkeylegend]

Have you got the correct batteries ? Did you get them from Merc or somewhere else ? You shouldn't have the battery error message after putting the new (correct) batteries in ..

R

Not necessarily. When I replaced the starter battery on my SL the battery warning/visit workshop message appeared and had to be cleared using star. All the other spurious messages caused by a dying battery cleared themselves.

 

[MD5]

Sorry if this is a naive suggestion, but the crank position sensor is a common fault on the m113 engine, and other fault codes/messages can come up due to flat batteries, which will remain until cleared.