Mercedes-Benz C-Class C200 kompressor auto 4 dr - How do i test the starter motor? and battery | Technical matters | Back Room Forum

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Thu 5 May 2011 17:08

Mercedes-Benz C-Class C200 kompressor auto 4 dr - How do i test the starter motor? and battery - Vinnychoff

My dads car stopped working, the battery was flat with only 6volts. tried to jump start but under the bonnet the starter motor clicked and hummed away. took the starter motor out and cleaned all the carbon brushes all inside greased the shaft and put it back together. with the battery only a year old (yusa). turned the key and it started 4 or 5 times on the key. today the same. battery was discharged adn the clicking noise and humming was under the bonnet. took the starter out and the gear was jammed......

Could any one tell me, also if im on the right track?

is the battery ok?

is the starter motor draining the battery? the humming noise under the bonnet?

thanks for your help in advance.

Vinny

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Thu 5 May 2011 18:16

Mercedes-Benz C-Class C200 kompressor auto 4 dr - How do i test the starter motor? and battery - injection doc

sounds like a battery issue or a drain on the battery.

The nominal voltage of the battery should be 12.2. volts to indicate a good battery. You may need to give it a good charge over 24 hrs to get the voltage back to take an accurate reading.

If you have an ameter and know how to use it then you could check for current consumption with everything switched off to see if there is a drain on the battery. I wouldnt recommend too many jump starts as this isnt good for the electrics !

If the battery nominal voltage is around 10.5-10.7 volts after a long charge that would indicate a duff cell.

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Thu 5 May 2011 20:16

Mercedes-Benz C-Class C200 kompressor auto 4 dr - How do i test the starter motor? and battery - Peter.N.

Check also that it is charging OK, you can do this by measuring the voltage across the battery with the engine running, it should read 14 volts+.

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Thu 5 May 2011 23:42

Mercedes-Benz C-Class C200 kompressor auto 4 dr - How do i test the starter motor? and battery - Vinnychoff

thanks for your help and ideas. i will check tomorrow.

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Sat 7 May 2011 09:41

Mercedes-Benz C-Class C200 kompressor auto 4 dr - How do i test the starter motor? and battery - Vinnychoff

i have the car running but am a bit stunned...

took the battery and starter motor to the dealers. battery tested weak so they replaced as it is only just over one year.

starter motor replaced with a bosch recon.

put all back togehter and tried to start with a small battery connected with jump leads, click. put the new battery in and click. connected the second battery to the car and the positive lead to under the red cap and .....click

I was about to give up then checked earth by putting the second battery earth to the engine and components but no change. tried checking all connections on the body of the engine. I could hear the pump i guess humming under the bonnet. then i reset the ecu clips forgetting the battery was connected.

tried to start the car and it turned over, started and had brake warning lights and was starting in safe mode. could not rev the car. switched off and it started ok again.

took it for a spin and the brake warning light cleared. engine management symbol stayed on. after a 5min spin round the block and back in the garage all faulty lights cleared. well now it says the pads need replacing but do not worry me....

now it has been started and seems to be ok. I just wonder if a component or relay was causing this to happen. i hope some of my mistakes might help others...although i hope your starter works all the time.

Vinny

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