[Mgs] Engine Frustration

Paul Hunt paul.hunt1 at blueyonder.co.uk
Sun Mar 21 08:01:04 MST 2010


The first thing you should be doing is looking at the ignition warning 
light.  Does it come on with the ignition?  If not there is an open-circuit 
back through the battery(ies) and battery earth cable to the body.

If it lights what does it do when you turn the key to crank?  If it goes out 
there is a bad connection back through the battery cable, batteries and 
battery earth cable to the body, or the battery(ies) is/are flat.  By 
testing on the battery posts with a voltmeter you can tell which.

You don't say the year, but from the 1970 model year all MGBs had a starter 
relay by the fusebox, so when you turn the key to crank can you hear either 
this or the starter solenoid operating?  If you have the relay, and it 
doesn't click, then you need to check the voltages round the relay - 12v on 
the white/red when you turn the key, 12v on the brown all the time, and 0v 
on the black all the time.  When the relay operates the white brown should 
change from a near earth to 12v.

If you hear the relay click, and there is 12v leaving it on the white/brown, 
check it is arriving at the solenoid spade.  If so, and the solenoid isn't 
doing anything, then the solenoid winding is probably faulty.  If the 
solenoid clonks but the starter doesn't whirr (surely you would have 
mentioned this?) either the solenoid contacts are bad or the motor brushes 
worn out or you have a bad segment on the comm.

PaulH.

----- Original Message ----- 
> ...  The next day tried to start it.  It tried to start then all of a 
> sudden the engine stopped turning over... 


More information about the Mgs mailing list