SL500 Not starting.

[C240 Sport]

My sons SL 500 not starting, key turns and it cranks slightly but won't start. It also won't start with the start button on the gear lever.
Just recently had a new auxiliary battery fitted not long ago. Any ideas on the problem please.

 

[ToeKnee]

Starter battery??

 

[C240 Sport]

Starter battery??

Its a new one.

 

[MikeInWimbledon]

Two batteries in the SL. You said that you have replaced the Auxiliary battery.

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Step one. Put the battery on charge - preferably with a proper battery conditioner, but if you don't have access to one a bog standard battery charger would get you up and running.

How long is it since he last used the car ?

 

[C240 Sport]

Two batteries in the SL. You said that you have replaced the Auxiliary battery.

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Step one. Put the battery on charge - preferably with a proper battery conditioner, but if you don't have access to one a bog standard battery charger would get you up and running.

How long is it since he last used the car ?

He used it a couple of weeks ago.

 

[ToeKnee]

Its a new one.

Ah, you only stated you had changed the auxiliary battery.

 

[C240 Sport]

Ah, you only stated you had changed the auxiliary battery.

Yea that's the one that starts the car. The other battery is fine.

 

[zipdip]

Check the earth on the starter battery,and make certain the battery leads are tight on the battery posts,if you have a scanner or can borrow one see if you have any codes,clear them and try again .

 

[MikeInWimbledon]

Yawn, There are two batteries in the R230 SL500, if that's the SL that he owns. (See video above)

There's a starter battery, which starts the car, and an auxiliary battery which runs all the non-essential items such as the roof, lights, radio, command etc. It's the Auxilliary battery that often goes flat, and which is likely to be changed by someone who wants to flog you a new battery for £100 - £200

You said that the Auxiliary battery had been changed.

If the car is not starting, it could be because the Starter battery is flat. By charging the battery with a battery charger, the car may be able to be started.

In general the R230 is "famous" ("infamous?") for running down its batteries if it's rarely used in Winter. People start the car, drive it a short distance with all systems consuming power, but not far enough to actually recharge the TWO batteries enough.

It may be something more complex, for sure - a faulty circuit or whatever.

But most likely, it'll be that he's got a flat starter, not auxiliary, battery.

 

[ToeKnee]

Yea that's the one that starts the car. The other battery is fine.

The starter battery on a R230 is under the bonnet and is used only to start the car. The auxiliary battery is in the boot and powers all other electrical systems. So, if you have changed the auxiliary battery but not the starter battery and the starter battery is flat the car won't start.

 

[C240 Sport]

The starter battery on a R230 is under the bonnet and is used only to start the car. The auxiliary battery is in the boot and powers all other electrical systems. So, if you have changed the auxiliary battery but not the starter battery and the starter battery is flat the car won't start.

Apoliges my mistake, Its the starter battery that was new and the other one is all good.

 

[Dickster]

What they said. If it cranks slowly the starter battery under the bonnet needs charging. Did you put a decent battery in it?

as far as i am aware there is no drain on the starter battery at all when not in use. So there may be an issue. I can leave my SL for weeks and it still starts easily - and I only keep a conditioner on the battery in the boot.

 

[C240 Sport]

What they said. If it cranks slowly the starter battery under the bonnet needs charging. Did you put a decent battery in it?

as far as i am aware there is no drain on the starter battery at all when not in use. So there may be an issue. I can leave my SL for weeks and it still starts easily - and I only keep a conditioner on the battery in the boot.

It's a brand new Varta silver.