ML 430 Battery Replacement--Procedure to not destroy codes?

[Jim Herold]

What special procedures, if any, do I need to follow when I remove and replace the battery in my 1999 ML430? I don't want to destroy codes/settings in memory.

Thank you--Jim Herold

[snays586]

I use a ordinary battery charger as a power supply. Connect the + line and ground in the engine room in meantime you replace the battery.
It works great for mee on a W 210 1999 model . No warning lights or lost memory after the replace.

W 107 350 SL 1971
W 210 E 240 1999

[Southern]

I use a battery style jump starter and plug it into the cigarette lighter. The ignition key must be in position II to allow the cigarette lighter to be powered.

[f4iman78]

A word of advice, don't have the key in the ignition when you change out a battery on a ML. Been there, done that. You're taking a change of messing up the "key slot" in the AAM.

[G-Benz]

I don't believe you lose codes simply by changing batteries.

My ML retained MAS codes despite a battery swap. and several attempts to get the CEL to disappear by disconnecting the battery lead.

You can get the ML to get rid of the CEL light in this manner...but the code is still stored. The dealer pulled two pages worth!!!

My SL WILL NOT lose the SRS fault code that I inadvertently set off by disconnecting a cluster harness without first disconnecting the battery...so I have to take it to the dealer to get it reset.

[ozzy]

Jim, It's good practice when changing a battery to keep power supplied to the car.
Not only for retaining memory and radio codes, but more importantly when you connect the new battery it helps prevent voltage spike, this spike can damage sensitive electronic components instantly.

I have two fly leads made up from 4mm wire, 3 meters long, one black (-) and one red (+ fused) with alligator clips at each end. You could use jumper leads but they are too cumbersome.

BEFORE YOU START, REMOVE KEY FROM IGNITION!

Using either a spare battery or donor car, first connect the red lead to the main terminal on the battery you are about to change or connect to the jump tower most Benz cars have, then connect other end to donor battery.

Now, connect black lead to a common ground on car and connect the other end to donor battery

Now you can safely remove and replace battery, just remember that positive lead is "ALIVE" so don't ground it. Start by removing positive lead and cover the end with a rag or anything non conductive (so it can't short out).

I have used this method for many years with no problems.

Good luck

[sgiles]

Subject: 1998 C230...Radio won't work after battery replacement

I recently replaced my battery and now my radio, when turned ON, just says WAIT on the display. I get no sound, nothing. What do I do to get the radio working again?

Thanks

[stevebfl]

You wait.... and then reinstall the radio code. The radio must stay on during the wait.

We use a small motorcycle battery... actually I think our current battery is a replacement for the ones in the "Jump box" we use.

I don't like hooking to the battery cables as it's just too easy to lose the contact while manuvering the battery. We use a special tool from MB's connector break out box assortment 220 589 00 99 00. It looks like an 80a maxifuse but the top has the same round connector receivers as most electrical devices (DVOM, DSO). We jump the device with a connector having a large fuse and replace the term 30 maxi fuse with the device and then hook up the small battery.

I would not advise using the cigarette lighter as the only way to do it would be with the key on. It then needs to power every circuit that works through the lighter wiring. It isn't too hard to imagine the load taking out the fuse and then you've lost everything and at the same time disconnected the battery with the key on; a not so nice event. Take the key out whenever doing any of these techniques.

[5280BENZ]

I don't know if your radio is the same type as the one in my 1999 SL500 but if an incorrect code is entered THREE times "WAIT" will appear in the display and the radio will be locked out for about 10 minutes. Note: the lock out time will only count down if the radio is left switched on.

[Jim Herold]

Battery exchanged completed and all codes preserved! I bought an Interstate MTP-93 battery--most powerful I could find. At Home Depot I bought 8 feet each of red and black #10 THHN wire and two sets of battery alligator clips. At Radio Shack I bought an in-line 50 amp rated #10 wire blade fuse holder (#270-1234) and soldered it in line on the red wire. I installed a 15 amp fuse (only trying to protect against an accidental short of the hot lead during the battery exchange). I hooked up to the donor battery as described above by Ozzy and retained power during the exhange, very carefully keeping the red lead protected to avoid a short. All was normal when done. Great procedure!

Appreciate the advice--