Mercedes Sprinter 313 - Intermittent Starting Problem, Humming Noise & Relay Replacement

Question

Hello, I have a problem with the 313 sprinter.
It's about starting up sometimes and sometimes it doesn't, and you have to try dozens of times until it snaps. When I do not want to fire, there is a humming noise under the driver's seat. Could replacement of the relay help or look for a problem elsewhere?
A relay that looks like this is yes

Anonymous · Answer

Looks like a glow plug heating relay. But it's rather not his fault, because since he is ticking, the problem lies rather in feeding his coil. Take a voltmeter and measure the voltage in the cradle.

stanisławpiotr · Answer

You need to ask for help from another person and when you turn the key to start, check the light to see if there is voltage on the starter solenoid.

Anonymous · Answer

Doprecyzujmy. If he doesn't want to start, doesn't he start or does he start?

aRASs27 · Answer

If it does not start, the starter does not turn, even you can hear the humming and nothing more

Gerri · Answer

I will also add my attention: 313 in no way identifies what kind of car it is. It is only a commercial designation and a car may well be twenty years and a half years old. You just have to guess from the content. You didn't even want to give the production date ... This is not a glow plug relay - this relay is mounted on the starter start line, in series to contact 50 in the ignition switch and is activated by the engine control unit. So on this line we have two pairs of contacts, which makes it very sensitive to overload. Just that the starter coil will have a short circuit between turns (this often happens!) Which will cause a current increase and such a significant voltage drop on the line that the starter solenoid will not work.

aRASs27 · Answer

Sorry for the 313 designation, this is more precisely the 2003 sprinter with the 2.2 engine. Is there an easy way to fix this fault? Because as for this relay I was in 2 automotive wholesalers (Gordon and ARPOL) and they didn't even have one and couldn't order

Gerri · Answer

So you are lying ... It is not a problem to check the stupid relay - even remove the lid and check if it closes and if the contacts are clean! I gave you a possible reason (not invented on the knee but found in this model), I gave the signal waveform - so get to work, get a little dirty on your handle, and don't count on changing the relay to do a miracle. Once again: first there is the ignition and the 50 contact is activated when the engine is fired, hence the current goes to the relay under the seat, and then to the starter. It is not a problem to check the current, check the voltage at each of the given points, even give the current somewhere and check if the starter turns off. This is no problem for a person who was careful in physics lessons at school I further suggest damage to the starter solenoid coil.