wrong battery terminal connection

[Rupz911]

Hi Guys,

Ive made a really silly error. This evening after coming out of a supermarket my battery just died. Dont ask why, as i am not sure why and its secondary to my actual problem at the moment.

So i had a spare battery in the boot and rather than using it to jump the car i just changed the battery as i could see whether the battery is faulty or not. In doing so, i connected the battery the wrong way around. There was a spark. which wasnt a bold of lightening, but at the same time it wasnt the usual spark you would get when you connect it normally.

Once i saw the spark i checked on line to make sure which is the correct way and i placed the cables on the battery and connected them via the nuts and bolts.

When i started the car i had 4 malfunctions, right fog light not working, left number plate light not working, something else which escapes my mind and it told me (in white) to visit the dealer. Also, i noticed the indicators were not working and my neighbour told me when i braked the lights were flickering. Finally, my central locking isnt working.

Have i broke my car or have a blown a few fuses?

Thanks in advance.

 

[Rupz911]

Hi Guys,

quick update. I went to the ca today and tried the remote CL , but to no avail and ended up using the pin key.

While the car did start up as usual, the indicators still do not work. Ive done some digging around and it seems it may be the SAM module thats blown. My own stupid fault but just in case anyone does do this its the SAM module located in the boot.

 

[Major774]

Live and learn from your mistakes

Hope it wasn't too expensive to fix.

 

[horgantrevor]

I don't know why mb don't fit a surge protector to the lead to prevent this from happening I know some mb care have battery control units

Pity about the Sam are you sure it's gone have you had a star test

 

[Rupz911]

Not had a STAR test done but form what i have read on another MB forum it seems that is the fault. The guy described EXACTLY the same problems with his sam unit.

While i haven't done a STAR test i will do so before i part with some cash as i think it would be prudent to do so.

MB quoted £337.20 inc vat for rear and £394 inc vat for front. But a STAR test eill be carried out before i purchase it. MB quoted £80+ vat for STAR.

 

[Auto-mobile]

It will end up needing front and rear SAMs, also battery, and that's if your lucky.

 

[horgantrevor]

Very hard to tell how many Sam units till star is done you may be a little lucky or not

The test is going to tell a lot

 

[Rupz911]

Thanks guys, im going to have to visit a garage which has a STAR machine so they can tell me how much its going to cost. I guess it wont be the first time they will have seen a grown man cry.

 

[parkman1]

Why do people insist on posting stupid remarks like this -
major774 Live and learn from your mistakes
Hope it wasn't too expensive to fix.
Rupz911 is looking for some assistance for a problem that anyone could make, we don't know the circumstances, but what he doesn't need is this kind of stupid comment.

I have seen this nonsense on all sorts of forums - people really needing some help, and some spanner puts up a comment like this. As if they are saying "Hahahaha, I would never have made this mistake so you are on your own, mate".

Just have some cop-on and give the guy some useful comments.

parkman

 

[horgantrevor]

Keep us posted good luck

 

[Dieselman]

It does look like the rear SAM is blown. Why not just fit a new one and see if everything else then works as it should?

 

[Rupz911]

Hi guys, thanks for the comments.

I've got a bit of an update. Just this evening i removed what i thought was the defective battery and put it in my garage to charge. But before i did i decided to measure the voltage. Strangely the battery measured 12V.

Now, the reason for me changing the battery outside ASDA (good offer on easter eggs at the moment ) was because as soon as i turned the ignition the lights went dead and the clock did a full turn etc. Not that its going to make a difference to me now but i was wondering whether anyone has experienced anything like this.

 

[Dieselman]

Did you meter the battery voltage under load, or as open circuit, no load?

If not under load, it will measure 12v anyway as there is no current draw.

12v indicates a mainly discharged battery.

 

[Rupz911]

The battery was under no load.However, The car had covered a long distance so i was quite confused that the battery was dead. Another thing, my battery has an indicator to let me know the condition and the window shows a green ball which indicates it is a healthy battery... well at least thats what is showing.

 

[Ted]

As DM says, the voltage means nothing unless the battery is tested under load.

 

[parkman1]

Hi, I had a problem with what seemed like a perfectly good battery, on a C180 1800cc petrol that I owned, last year. I went on two journeys one morning, and then on the third journey, when I got to where I was going, I parked up and went into the building.

I was inside for about a half hour, and when I came out the car was as dead as a dodo, nothing, nada. Absolutely flat, not even the windows worked. So I called the AA and the guy did the check and there was 12vdc, but the battery was knackered.

Just the vagaries of car batteries, I think. The older acid batteries can just suddenly give up the ghost with no warning. I fitted a new battery and everything has been fine since, and my son has the car now, and has had no power problems.

I have a W211 220 cdi [diesel] and it is a different ballgame with these. If you do short journeys, such as nipping out to the shops and back again, you will find that the battery will rapidly start to be reluctant to start the car. It takes so much juice to pre-heat and start the diesel that you soon see the dashboard display telling you that certain functions have been disabled to protect the battery.

Fortunately, I have enough time these days to take the car on a bit of a run of about 7 or 8 miles to get the engine warm and give the battery time to re-charge. The 220 diesel is not the ideal car to use for very short journeys.

Still, I think Mercedes are very kind to us by persuading us to buy a diesel to save on emissions, and then helping us again by making us walk to the shops :bannana::bannana:

parkman

 

[Rupz911]

hi Guys,

Just enquired with MB specialist who will charge £40 (forgot to ask if it inc vat) to put it on STAR and if no fault is found they dont charge. Will take it on next week and see what the outcome is. Im expecting a shopping list of faults so anything less will be a bonus

 

[Rupz911]

Hi Parkman,

I too have the W211 diesel and i know all about short trips and voltage. But i had just done a good few trips with 40-50 mins of travel for a few days. Friday was a couple short trips and so was sat. sunday the car had a 1hr round trip and monday evening it went to ****. Thats whats strange to me.

I never had this problem with my Audi before and i drove it more frequently for short trips then i did my merc. But, i have a visit with a merc specialist next week so i will take a look and see what they say.

Cheers for your help and support

 

[Rupz911]

Hi guys I have a quick update for you all.

Not sure if you're allowed to name and shame an indy so i will steer clear of that, but just be warned that a merc specialist on Gwendolyn Road in Leicester is NOT recommended.

I gave my car to a family friend who took it to another merc specialist. He changed the rear SAM unit and the car is now functioning. Only thing i have noticed is the radio and the driver adjustable electrics on the seat are not working. Ive checked the front fuse box in the side of the dash and the rear fusebox on the left hand side of the boot but the fuses are all in tact. Is there anything else I have missed? I assumed it went on STAR hence the reason for the rear SAM unit change.

 

[Auto-mobile]

Sounds like it needs some of the settings changing, through star.