C200 Kompressor Flat Battery

[therenster]

Hi all, newbie here! I have some electrical issues im looking for advice on and im no technical mechanic guru, so take it easy on me!!

The above car is my wifes, its the compact 2001 model. She was having problems when leaving the car stationary over a weekend that it wouldnt start on a Monday morning and the battery required charging. We have now put a new battery in and the problem persisits.

Does this mean the alternator is more than likely kaput?? Or having read some previous posts maybe the voltage regulator?

My other questions are (dont laugh) where or how can I find the alternator and voltage regulator? And if I was required to replace them is this a fairly simple task for a novice? And any helpful ideas as to the best place to surce these parts?

Thanks in advance, im getting annoyed with having to get up extra early every Monday morning to jump her car!!!

 

[BlackC55]

You may have a current drain problem. (somthing is staying on draining the battery) A good specialist/auto electrician should be able to measure this for you. (expect 0.03A to 0.05A)

The alternator is located under the supercharger and is not that hard to fit. The regulator is located on the rear of the alternator. The v-belt at the front of the engine rotates the alternator.

The ouput of the alternator needs to be measured too and a specialist or auto elec can also do this for you.

 

[therenster]

Im ok measuring current etc. I have a multimeter. Im an Electronics guy so electrical is a bit new to me! Do you have some pointers as to what to measure and where to check for a current drain?

 

[BlackC55]

Right.......

Get a good multimeter first.

Lock the car with the bonnet open and the bonnet catch pushed over (to falseify a closed bonnet). Connect the meter in series. Remove the negative battery terminal but have one meter terminal with croc clip attached to a good body earth and the other to the negative pole of the battery when you remove the negative battery cable. This is to keep the circuit and have the meter in the middle of it.

You wil have to wait 30 mins for the current to settle down.

I hope this all makes sense. if it doesnt PM me and I will give you my phone number and explain it .

 

[television]

OK here we go.

The running voltage of the car is 13.8-14v.
The engine off voltage is 12.5v.

To measure the current you must do this without breaking the circuit.

For this you need 2 leads on one of the terminals on the test meter, one lead with a probe and the other with a crocodile clip. Clamp the single lead from the meter to the battery cable clamp, slacken the clamp, and put the meter lead with the probe on to the center of the battery post, slide the clamp up the probe and put the second lead on to the battery post, and your circuit stays intact, you can then read off the current flowing.

 

[jberks]

I seem to remember Malcolm a while back mentioning that sometimes the data bus doesn'[t shut down properly, leaving a number of items active. A known fault I believe.

 

[television]

I seem to remember Malcolm a while back mentioning that sometimes the data bus doesn'[t shut down properly, leaving a number of items active. A known fault I believe.

If you have Command it does not always go to sleep after ½ hour, I have that fault on my car, other wake up components can behave in the same way.

The easy way is to go around and remove the fuses one by one, observing the meter

 

[therenster]

Right.......

Get a good multimeter first.

Lock the car with the bonnet open and the bonnet catch pushed over (to falseify a closed bonnet). Connect the meter in series. Remove the negative battery terminal but have one meter terminal with croc clip attached to a good body earth and the other to the negative pole of the battery when you remove the negative battery cable. This is to keep the circuit and have the meter in the middle of it.

You wil have to wait 30 mins for the current to settle down.

I hope this all makes sense. if it doesnt PM me and I will give you my phone number and explain it .

Makes sense so far, to simplify it im testing between a good earth on the car and the negative battery terminal? If this is pulling any sort of current something is running on the car to pull the battery power and then its a case of finding what it is!?

 

[therenster]

Think I got it wrong!! I need 1 probe of the meter on the detached negative lead, and 1 probe onto the negative terminal on the battery. Thus, meaning the circuit is intact but with the meter in series??

Ok, think thats it, cheers guys, ill have a go tonight and let you know the outcome.

If the meter shows a current being pulled I should start pulling fuses to find out what is pulling the power? and try to narrow it down to something.

 

[television]

I have said how in post 5, its the only foolproof way, if the current is abnormal, pull the fuses one by one.

 

[Blobcat]

Boot light can take 1 amp and drain the battery quite quickly. Have you checked that it is going out when you close the boot ?

 

[therenster]

I have said how in post 5, its the only foolproof way, if the current is abnormal, pull the fuses one by one.

Excuse my stupidness please! I never quite understood all the clamping/unclamping, can you run it by my thickhead step by step?

What is a normal current reading and an abnormal current reading?

 

[therenster]

Boot light can take 1 amp and drain the battery quite quickly. Have you checked that it is going out when you close the boot ?

No :Oops: Will do now though

 

[television]

I will do a DIY for this shortly

This is the meter lead set up

 

[television]

Excuse my stupidness please! I never quite understood all the clamping/unclamping, can you run it by my thickhead step by step?

What is a normal current reading and an abnormal current reading?

The clamp is on the end of the battery cables (nut and bolt), also a clamp is on the end of the meter leads (sprung crocodile type)

Normal current (quiescent)depends on the car not more though than 100m/a after ½ hour

 

[BlackC55]

Normal reading 0.03A -0.05A.

Anything significant above that then you know the current is draining

 

[therenster]

I will do a DIY for this shortly

This is the meter lead set up

Excellent, thanks, cheers in advance for the DIY as well, great help

 

[therenster]

Just spoke to the missus and she informs me (2 months later!) that the boot catch has been playing up. When you pull it to open it doesnt always work. You need to push it back into position before pulling it for the electric switch to work, maybe this has lead to the boot light staying on? Guess it gives me a good starting point.

Darn women! :wink:

 

[television]

Just spoke to the missus and she informs me (2 months later!) that the boot catch has been playing up. When you pull it to open it doesnt always work. You need to push it back into position before pulling it for the electric switch to work, maybe this has lead to the boot light staying on? Guess it gives me a good starting point.

Darn women! :wink:

You could invite her into the boot to see if the light goes out:Oops: :Oops:

 

[tubby]

Battery Drain

Hi all, I checked the drain on my 2004 C180K Estate last weekend using a DC clamp ammeter after about 40 minutes the drain was 120ma. The car has the standard MB Alarm/immobiliser. No Command.

Does that seem Ok?

The reason I ask is, I the battery died last February and was replaced by MB under warranty but as my warranty is up later this month if something needs attention then now is the time!!!


T