Starts, don’t start, Start Ahhhhhh I need your help

[*BigMac*]

Hi guys and girls

I need your help on a mater that is driving me insane

I have a 1999 C class Merk 250TD Auto

The problem im having is a intermittent problem - when I put the ignition key in ( its one of the electric keys not a blade type) and turn it – I can turn it to the second position and get all the ignition lights on, but third turn of the key will not start the starter motor (not a click or anything)

As I say this is a intermittent problem, some times I can go for days without it starting, then it will start – for instance it started today so I put it on the drive and had a good mooch at it, and its started a few times since, then again its not started a few times.

Things ive checked are
Starter motor – power going to it and if you bride the connections it spins
Heater plug relay – working fine.

Im wondering if the inhibiter switch from the gear box is faulty, I’m I right in thinking that if that was faulty the car would not know that it was in park and would not start / turn over??? Anyway of testing it??

Can anyone help or suggest anything else I can try.

Cheers Steve

 

[television]

Its possible that you have a starter lock out relay K38 I can look it up later, are you saying that when the key is turned to start there is no voltage to the solenoid

 

[*BigMac*]

Sorry never checked voltage at the solenoid- will do tomorrow.
Don’t know in all honesty im completely lost with it, I just know 3rd turn is doing nothing most the time.
This relay you talk about where would it be??

Cheers for your input

 

[television]

Sorry never checked voltage at the solenoid- will do tomorrow.
Don’t know in all honesty im completely lost with it, I just know 3rd turn is doing nothing most the time.
This relay you talk about where would it be??

Cheers for your input

Many cars around 98-99 had a lock out relay that was to isolate the starter from the alarm, if you have one its on the bulkhead behind the radio, and they did get bad connections on them

 

[*BigMac*]

ahh i will pull the radio out tomorrow and have a look. thanks for that

 

[television]

ahh i will pull the radio out tomorrow and have a look. thanks for that

As I said some cars dont have them but many do, the spade on the relay arc's and make a poor contact you can wire it out of action if you want to

 

[*BigMac*]

would i be able to find out from typing my chassis number in that russian web site if mine would have this relay

 

[panason1c]

Am I right in thinking that if that was faulty the car would not know that it was in park and would not start / turn over??? Anyway of testing it??

Can anyone help or suggest anything else I can try.

Cheers Steve

Next time the car wont start try holding the key in the start (cranking) position whilst at the same time jiggling the gearlever between N and P......if the starter motor comes to life the likelyhood is that it is the inhibitor switch that is faulty.

 

[Bolide]

My instinct says ignition switch

Nick Froome
www.w124.co.uk

 

[BlackC55]

My instinct says ignition switch

Nick Froome
www.w124.co.uk

That or starter motor.

 

[*BigMac*]

Bit of a update

Not done much today as its pidaling it down here today

Got a test lamp and earthed one side and put the other to the solenoid live wire – then turned the car over, (3rd turn of the key) it should have turned the test lamp on.
But nothing.

However got a long screwdriver and bridged the starter live and the solenoid and it starts.
So now i know no power going to the solenoid.

Will have to get a set of radio pins to take the Merk CD player out, and check that relay out

Any walk through’s on here on how to remove and bride the relay

Cheers for all your thoughts so far