Mercedes R230 SL55 glove box light and battery drain

This is a short video detailing how the glove box light works on your Mercedes R230 SL55 AMG. If the plastic lever which operates the switch breaks, or becomes detached, you can find that the glove box light stays on and causes your consumer electrics battery to run down much faster than it should. Similarly, if you have cause to remove this light to change the bulb for example, and you do not know how to put it back in, you can end up breaking the light fitting which in turn leads to lever switch not operating correctly and your consumer battery going flat. The end of the video gives part number and costs for both the glove box light and the lever which operates the switch.

[@ingonannsen9869]

Thank you Mike for this very instructive video! I was struggling to put my light back in but with your instructions it should not be a big problem. I’m always surprised how these guys make easy things complicate. In all my older cars this light was one of the easiest things to fix, but not in modern Mercedes! Keep posting your videos! Thank you, Ingo

[@MikesMercsandothercars]

Thanks for your comment and I'm really please that this simple video has already helped a couple of people...and yes...on all my other SL's the glove box light is the most simple of things to fix! Mike

[@ingonannsen9869]

I fixed my switch as you described, very easy procedure! Unfortunately the repair didn’t fix the light problem, after closing the glove box, the lid sprung back a little bit, enough to turn the light on again. I couldn’t find an adjustment to keep the lid really closed, so I have taken out the light bulb and fixed the micro switch as if the plastic lever would hit it, hope this fixes my battery drain problem!

[@MikesMercsandothercars]

@@ingonannsen9869 Taking the bulb out will do the trick. There are a couple of ways to ensure that the glove box closes in the correct way. 1. Adjust the two rubber stops mentioned at 3.58 in the video 2. Move the actual catch on the glove box. This is held in with two philips screws mentioned at 2.18 Good luck. Mike

[@cornelchin96]

​@@MikesMercsandothercars 8n

[@celts153]

Nice Job ! What i don't understand is that the Computer should have Cut off the light when car is closed. It is normally designed like that... Will do a test on mine leaving glove box opened, pretty sure that if you close the car, the light shut off. But once again, good job !

[@celts153]

I have tested it, and the light still stay on.... it seems weird, but explain your problem.

[@MikesMercsandothercars]

Thanks for your comment - I would have thought so too but here is what I think happens.... 1. If the lever switch is operating as it should, the microswitch send a signal to the SAM to start a timer when the glove box is opened. If you leave the glove box open. it will time out just like the boot light and door lights. When you close the glove box, the lever operates the microswitch and sends a signal to the SAM to reactivate power to the glove box light terminals. The light doesn't actually come on with the glove box closed because the lever is pushing down on the metal contact. 2. If the lever is missing, the SAM never gets a signal to start the timer so there is constant power to the glove box light terminals. When you open the glove box, the light is on as you would expect, BUT...you never realise it doesn't go off when you close the glove box. I seem to remember that there was a weird 8v across the microswitch terminals. It is early days, but at least two subscribers have just contacted me to say that having checked their switch, it is indeed missing...and their battery runs down....I gather manyR230 owners have their consumer battery on a trickle charger...maybe not realising that their glove box light might be the source of the drain. Thanks again for all your help. Mike

[@vladimirfrakt3018]

Mike, that is indeed correct. I think my mechanical lever was partially snapped in, or the bar to the light was slight bent (due to being pushed on over time). With the glove box closed, the micro switch was engaged, but the light stayed on (tricking the computer (SAM) into not activating the timer. It’s a shame that the scenario created a false negative. I looked at the previous service records, and it looks like the previous owner complained about the parasitic draw, but they diagnosed it to fuse f21 (dashboard), and wanted him to replace the instrument cluster😢, which he declined and just lived with it.

[@billbord3205]

Hi mike ,as soon as you put up this vid I had look at mine and sure enough switch was MIA and when I got the glove box out I found it on top of the box ,when I replaced it I found the long flat spring contact had been pushed over and broken the delicate plastic retainer so requires new light.I think the other switch might be connected to the central locking maybe good vid cheers

[@MikesMercsandothercars]

Well its good to know the vid might have helped someone. Did you have a problem with your consumer battery running down I wonder? Mike

[@billbord3205]

@@MikesMercsandothercars I did and i thought it was the phone charger ,bet there are quite a few out there sitting almost hard wired to battery maintainers because of this problem.Thanks again for posting! Cheers

[@mauricemalone6717]

if the switch is broken. light doesnt work . will this still be a problem with the battery drain?

[@MikesMercsandothercars]

Hi - as long as the light isn't permanent on, it shouldn't drain the battery - you could take out the bulb to be safe. Problem with that switch mechanism is that when it breaks, the light is on. Mike

[@mauricemalone6717]

@@MikesMercsandothercars thank you

[@mhyahiyaalrifai]

Oh bro after I saw this video I want to the car and the tongue is all in and the light is always on Omg thank you You are and angel hahaha

[@MikesMercsandothercars]

Thanks for your comment - that light on permanently, will drain consumer battery after a few days. I think the car I bought had this problem for many years and the result was that the battery would often drain below 11.7v and stay there for days/weeks until the car was driven again. Eventually, this will ruin your battery and it will no longer hold its charge. It took me a while to figure that out. Mike

[@mhyahiyaalrifai]

@@MikesMercsandothercars hey Mike I'm not really into fixing it right now since I don't even use the glovebox If I disconnect the wire is that will be an issue ?

[@MikesMercsandothercars]

@@mhyahiyaalrifaiI think that disconnecting the wire or taking out the bulb should do the trick....BUT you may find that the switch being open, keeps on another module. For some reason that light bulb switch appears to controls more than just the light bulb....eg its not just a simple on/off switch. Mike

[@mhyahiyaalrifai]

@@MikesMercsandothercars I'll do it tonight and update u

[@ash44roberts]

Another great video Mike! I note that on my 2005 SL55 there is NOT a 3.5mm auxiliary jack port in the glovebox or anywhere else. Would you know if this is something that could easily be retro fitted? Thanks 🤞

[@MikesMercsandothercars]

Thanks for your comment. For some reason Merc did away with the 3mm jack in later versions of the Command unit. I think that rather than retro fitting a 3mm jack, the way to go is to replace the CD changer behind the passenger seat with a unit which has built in blue tooth. My CD changer doesn't eject so I may do a video on this at some stage...which will give me (and you!) a better idea of what connects exist down there. Mike

[@ash44roberts]

@@MikesMercsandothercars - Great, looking forward to that video. Having to rely on a Bluetooth speaker in the car on long European drives gets a little tedious! 😂

[@williamnichols9853]

I had the same problem, I just took the bulb out

[@MikesMercsandothercars]

Yep - that will work although a new switch from Mercedes is not too expensive. Mike

[@Amg641]

Hi Mike would you know what guage wiring is used for the can bus connectors?

[@MikesMercsandothercars]

Hi - If it was me, I would use an accurate set of calipers to measure the outer diameter of the wire....and then I would count the copper strands to see if there were 16 or 32. Have a look at the link below and it will give you a good idea: www.autoelectricsupplies.co.uk/c/cable You have two basic choices - 'standard' or 'thin wall'. I used the latter (32/0.20, 1.0mm², 16.5A - cable OD 2.0mm) when I made up the wiring loom for the red 280Sl because you need to crimp a special plug onto it. To fix the folding roof on my SL55, I used standard 14/0.30, 1.0mm², 8.75A - cable OD 2.6mm. Slightly thicker because the wires are bent every time the roof goes up and down. Mike

[@Amg641]

@@MikesMercsandothercars would it matter if the amp rating was high? I have a 27amp cable suitable for charging circuits it says

[@MikesMercsandothercars]

@@Amg641 No not really - it just means the wire might be a bit thicker. It would matter if it was too low a rating and the cable melted. Mike

[@Amg641]

@@MikesMercsandothercars would you know where terminal 15 N10/10 is located? And is N10/10 the actual drivers side sam unit? Let me know please

[@MikesMercsandothercars]

@@Amg641 No sure - I was trying to get hold of a wiring diagram as I don't have one. What issue are you trying to fix? Mike

[@kavindugilshan]

German engineering 😬

[@MikesMercsandothercars]

Thanks for your comment - At some stage, I plan to do a whole video on this car...along the lines 100 things to love about the R230...there are so many highly (some would say 'over') engineered things I have discovered. Mike

[@tombiondi9969]

Agreed, a standard plunger switch would have worked just fine.