SL500 Rough Idle, No Power, BAS Code
 

A friends 1998 SL500 needed a jump, would not start only clicking. Charged overnite and got it started in the AM. Would not idle smoothly or over 500 rpm, and BAS code displayed. No Power, floor accelerator no rpm's over 500.
Replaced battery, car starts great, but still no idle( or with it floored) over 500, and BAS code displayed.

Battery voltage (MB replacement) 12.47V. At idle, 14.17V.
Last thing done to the car was installation of Sirrius radio by pro shop.

Where should I look.?

Sorry All my experience is with diesels, first time with the great looking SL owner. The convertible looks good as well.

Thanks for your assistance,
Gary P

The early 129's had an over voltage protection fuse and relay. It was intended to protect the electronics from voltage spikes like those which can occur when jump starting. The fuse blows and causes the symptoms you describe. I don't know if that was carried through to the later models like yours. If you have one, in the old 129's, it is located under the hood on the passenger side at the rear ( near fire wall ) under a plastic cover held down by 4 or 5 large philips head screws. In my 1991, it is a blade type fuse on top of a plug in relay.

It was carried through in the form of the "Base Module" (picture). The module has three fuses mounted externally, and one of these may be blown.

Thanks for the info, I will check the fuses tonight, and report back.
I searched the pics of the OVR and external fuses.

Thanks again, you all are soooo very much appreicated and the money saved is especially appreciated before the Holidays and in this economy.

Gary

Checked the fuses with a meter, all three fine. Still no power.
Didnot pull module, quite tight within holder. I would have but not my car.

Towed to Indy, will advise from here.

Thanks,

Bump. So what happened?