Vader94

Afternoon guys, need some help.
So my SL55 2003. I Have a red battery light ‘visit work shop’. I bought it with this light on. Mechanic said didn’t seem too much of an issue.
As soon as i start the car it’s there.
Car starts fine, works fine. No issues.
Prev owner swapped both batteries and battery control module within last year.
both batteries on idle and off seemed to be within the parameters.
Diagnostic says B1828 fault relay k57 fault. Replaced k57 from merc. Light still there. Alternator replaced and voltage regulator replaced too.
Did the whole disconnect batteries properly etc rest thing.
Any one ever had something similar ? Any advice would be greatly appreciated.

tonylinc

That is odd for your mechanic to say it's "not that big an issue". Obviously there's a problem. With the R230 electrical warning can mean a bigger problem is coming. Hopefully your new alternator is a genuine Bosch and not a cheap brand, the previous owner of my SL55 installed a cheap Duralast alternator which failed one day and caused stupid expense. But considering what you've replaced, I can't think of what to do next, although there are guys on here who probably will. I assume you connected the (new) batteries in the right sequence. Underhood first, trunk battery last. Maybe it's possible that the car just remembers a fault that's no longer an issue but needs to be cleared with SDS? Just guessing though, and that seems unlikely.

Vader94

@tonylinc
thank you for your response.
Maybe I have been stupid here. So I replaced it with a Bosch alternator but it was used but was told it was a working unit just wanted it in asap. Do you think I should replace it with a brand new Bosch alternator ? Yeah did the sequence with batteries but to no avail sadly. Also I cleared it with icarsoft which says it is cleared and as long as that’s plugged in that light doesn’t come on as soon as I take it out and turn it on. The light returns.

cdk4219

There could be many problems, but with this electrical system you certainly don’t want to fool around. If your mechanic is telling you it’s no problem, you would be advised to get a different place to go.
More than likely yiu are going to have a Battery control module problem, and that’s a big problem for your wallet. These cars have a problem spontaneously combusting because of these control modules. It is a well documented problem and more common than most people think.

It is very important to have 2 new batteries, make sure the batteries are trickle charged, and really never jump start the car. If you can’t diagnose this yourself, you need to find a mechanic that knows these cars. Not paying attention to that light will probably lead to many more problems.

Vader94

@cdk4219
thanks for the reply.
I think I’m just going get new batteries for my peace of mind. Battery module only few months old and did check it. Going to book it in with a renowned specialist too. It ‘looks’ ok but maybe it has gone. I have a ctek will that do or do you recommend any?

cdk4219

Ctek will be fine, besides the alternator, there is a fuse under the subwoofer that sometimes blows, and I believe it triggers a battery light. Unfortunately when I encounter the light, it’s usually the bcm.

Vader94

@cdk4219
the fuse has been replaced.
hmm I think your right. Temperamental things it seems. But alas has to be done. Thank you for the advice. I’ll also see what the specialist says, if they find anything strange.