starter motor spins the wrong way!

[billythefish]

Been waiting ages to start my old 250s merc up as it has never been fired up since I bought it 5 months ago, due to the fact that so many bits were missing!
When I did try to fire it up I notice that the starter motor was turning in the wrong direction so as not to engage the flywheel.
The earth wire on the car is negative, so for me to spin the starter motor in the opposite direction does this mean I have to reverse the polarity to positive earth? seems strange I've tried two starter motors with the same result!

any ideas would be welcome

billythefish

 

[grasmere]

hmm - are you 'positive' thats its a negative earth design?You said its an old 250?

Other than that you could try using eg jump leads diretc from a battery on the floor to the electrically disconnected starter motor to see briefly if you can alter the direction of spin with reverse polarity.

I assume the solenoid still thows the starter shaft into the starter gear ok?

 

[billythefish]

according to the manual it is a negative earth, the earth cable to the battery is attached to the inside wing and to the engine.
I really do not know anything about the electrical system on a car, that is why I was hoping someone out there could help.
The starter motors (I've tried two ) when juiced up fires inwards rather than outwards toward the flywheel.
The starter motor connection has two large wires and a smaller thin wire attached to it, I've tried reversing the wires but the same thing happens!

 

[219]

The 108 series cars are most definitely negative earth , even my 105 series Ponton which is another 10 years older is also negative earth as are all 'modern' (i.e. post war) Mercedes cars that I have come across .

Are you sure you have the correct starter motor for your car ? An auto electrical specialist ought to be able to help.

 

[billythefish]

Good question Pontoneer,
I can't honestly say if it is the correct starter motor or not however, it was in place on the engine when I bought the car from a Guy who is a mechanic,so I assumed it was the correct one.
I will check the number on the starter motor to confirm that it is the right one.
many Thanks
billythefish