Rharris612

Bought the car for my wife, who always wanted a red SL. Haven't put any miles on it but playing around I've seen a 'Telephone please subscribe message', the 'red battery light' once, and the 'All Services off' once, I have read where the red battery fault is the starter battery and sounds like voltage regulator or Battery Control module. Have ordered both. The rear 'Consumer' battery (All services off) could also be the Battery Control Module. Understand the only way to delete the Red Battery error is to go in with a Star Diagnostic Tool and delete it. Ordered a Star device from China.
The seller had this one and an 88 SL. They had their shop look at car and they replaced both VC gaskets, RR strut, brakes, and rear engine seal. (Not sure why all that had to be done. Car Fax says it is original miles.)
Everything else seems good. Car is exceptionally clean, inside and out.
I'm posting to primarily thank all of the posters here who have helped me research these issues both before and after decision to purchase. This is the best forum for these cars.
THANKS!

FxFormat

Rear engine seal is a very common leak among RWD cars. In your car the mileage didn't deteriorate it, time did. Rubber gets dried and brittle over time. Congrats and enjoy! These cars are a bargain, hands down this is the most depreciated car i've ever seen. This and the S600/S65.

Someone on YouTube bought a 2006 S65 with 147K miles, for a whooping $3700. ABC system leaked but all else was good.

Rudeney

The red battery icon means that voltage has dropped to a low level, which may not be able to power the SBC (electrically boosted brake system). Everything in the car, except the starter, is powered by the consumer (rear) battery. The starter (front) battery ONLY powers the starter. However, in a low voltage situation where the consumer battery is weak, the BCM can ad the starter battery in parallel as supplemental power. It cannot do the opposite - if the starter battery is too weak to power the starter, the consumer battery WILL NOT be switched in to help.

If there is a fault in the BCM, the red battery icon may remain on and require a proper diagnosis and repair to extinguish it. If it's just a low voltage situation, and the battery is eventually recharged or replaced, it will extinguish itself.

Since you are getting the read battery icon and the "consumers offline" messages, I suspect your consumer battery needs to be replaced. But you should also check the alternator. On mine, the alternator failed so not only did I not have operating voltage for driving, the batteries were not being maintained. I replaced it, and then not too much later ended up replacing the consumer battery.

Rharris612

Thank you! Several of your posts Rudeney have been very helpful. Actually I think you've posted some doc's I've printed out to keep for future work.
Would you replace the Alt even if when engine is running the battery voltage goes up from 12.+ to 14.+.?
Batteries both appear to be new (starter is MB, Consumer is auto-parts but does appear to meet spec.) but the consumer battery does seem to have some drain over night or so. I do have the voltage regulator on order. Thanks, in advance for your response.

moretech

Welcome to the forum!! In here you can learn a lot about how your car works. Study your owners manual alot to begin to learn all your car's features. My personal experience has been for my '03 more mechanical (ABC system) than electrical headaches. Good rear (AGM) battery a must. Enjoy

moretech

Rudeney

No if you are getting 14v at idle, the alternator is working properly. The consumer battery will drain when the car sits. Most peopel who let is sit idle for more than a week will but a trickle charger on it. What I would do is see how the voltage fluctuates. If it's below 12.4v each morning, then either you have something draining it more than normal, or the battery is in need of replacement. Sometimes there are date stickers on the battery. If it's over 4 years old, I'd replcae it.

moretech

Let us know how this low mileage sl works out for you after putting some mileage and some time on the road on it.

moretech

Rharris612