Getting to battery on 355GTS

On my right hand drive version the battery is on the right side. For US it may be on the left side.

Just remove the front wheel, unscrew the panel just ahead of the wheel and you'll see the battery.

Regards,

cwwhk

 

It's always on the right hand side. When you take the right hand wheel off there are 5 cross-head screws securing the access panel that cwwhk mentioned.

The securing clamp which holds the battery in place has a 10mm bolt. The Battery clamp bolts are 10mm also.

Remeber to turn-off the isolator, and to disconnect the -ve terminal first and reconnect it last. This minimises the potential for inadvertant arc-welding.

 

They do this in the manual - just to mess with you

On both the left hand drive and right hand drive - the battery is located on the right side of the car - (as mentioned above). It takes about 20 minutes to get to and replace the battery.

You as many - have ripped apart the boot - looking for the thing for the first time - do not feel alone

 

The battery is on the right side on LHD cars too, and there's no way to get to the poles without removing the front wheel and the myriad of screws holding the panel.
However, the better way to charge your battery is to read your manual, open the engine cover, remove the RHD cover plate along the C pilar (3 screws). Underneath you'll find two charging poles, the positive one covered by a cache marked +. All you need to know is that these poles are "behind" the battery switch which is in the front wing trap beside the CD changer, so the battery circuit must be ON. No charging if it's off.

 

You will need to turn it back on to charge as ZE described. Also I would not advocate ever turning it off unless required to perform some sort of service that required it as a safety measure.

 

I turn mine off when I know it's not going to be used for a few weeks to avoid battery drain

What problems do you envisage by doing this?

 

I often times leave mine off - if I go more than 1 week without running it. There really are no concerns in doing this - minus two things:

1.) you will lose all settings on your radio

2.) when you turn it back on - when you start the car - you should have all components shut off - Radio, Air, heater, etc. Let the car run without touching the Accelerator or moving the car for 10 minutes or so (some will say 15 - 20) but 10 should do it. This gives the ECU's time to reset to the idle position - which is where you want it.

Rich

 

You might be able to charge it through the cigarette lighter socket.

 

Yes you can. I know a few people that do this. I did it on my 355 for a time, but the dealer installed an on-board charger.

I still charge by this method on my BMW. Just remember to only do this with a low amperage charger like 1.5 amps or less.

Dave

 

That method will not reestablish the adaptive memory on cars with an engine management system of a version higher than motronic 2.7. On later cars it is a much more involved procedure and Bosch will not share what the driving cycle that is required to relearn it. Have you heard of all those cars that have trouble with check engine lights? It is a far more common complaint on cars that have their batteries turned on and off regularly. The technical department has long wished that the battery switches were deleted but as yet it has not been done.

 

Some excellent information there, thank you.

Fortunately mine is a 2.7 so I appear to be ok

 

Per ze_shark's comments, this is how I also used to charge the battery in the F355. To remove the RHD plate cover you will need a set of Allen wrenchs and it is 3 bolts. What I did after removal was attach a permenent connector cord to the charging poles so that I could easily plug in the battery conditioner (from Airflow UK) whenever the car was going to be sitting for more than a week. I used this system for over a year without problems.

 

Hi, Do you have any idea what the relearn procedure is for 5.2 ?or where I can find out.

 

Bosch is famous for being very tight fisted with any information. As I understand they share it more freely with Mercedes Benz than anyone else. If you can find an engine management manual from them for a system in the low 5's generation wise you may find the information you need. I know it involves multiple startups, cold startup etc.

On many of the late cars many systems besides just the Motronic have learned information that is lost with a battery shutoff so much so that when servicing I often don't turn the battery off, I just disconnect the cable feeding that part of the car. If you have a 456/550 or later car when you open the door the window retracts slightly. If the battery is off it will not do that. when the door is closed the window will harm the weather stripping, I saw a 360 break a window when the door was closed and the battery was off. Just leave the battery on. If you will not be driving the car for a period, put on a battery maintainer of some type and use it.

 

If you wish to charge your battery through the cigarette lighter socket, buy this charger (or one similar): http://snipurl.com/7cod

Then take one of the "pigtail" adapters, and splice on a cigarette adapter plug like this: http://snipurl.com/bkwr I prefer this one, because it includes an 8 ft cord....so you can run it some distance. The cord is thin enough that you can usually safely close the door on it.

Dave