the Starter Motor
We started having intermittent problems with the car not turning over when starting it. When I tried to start it something would click (probably the starter relay) and there was a light humming/buzzing sound but no action. She jump started OK as long as the negative jumper lead was on the engine block. The electrician said to remove the motor and he would test it and it tested OK and I tested the positive ciruit (starter relay was working & cables tested OK with my multimeter). I refitted it and still no go… Blimmin electrician. Then I thought “The positive circuit seems OK. What else is there? Well, duh, the negative!” I thought there was a bad connection between the starter and the engine. I connected a jumper lead directly from the negative terminal of my battery to the body of the starter motor – bingo, she started no problem! I then talked to another electrician and he said the negative lead between the battery and the motor sometimes goes (he remembers a case where the choke cable was the ony thing grounding the engine of one car) and the way to test it is to hold a voltage meter between the negative battery terminal and the motor while starting. There should be an excellent connection between these two so there should be very little voltage between them. If the connection is bad, then you can see several volts between them while starting. What that tells you is that the resistance of the wire to the engine is substantial compared with the resistance of the starter motor itself (a simple resistor divider circuit if you’re into electronics). In my case I saw up to 9V between the battery and the engine which means that of the 11- 12V available, the starter was only getting about 2-3V – not much to work with! So the problem was that the engine was not grounded properly – the cable probably broke while 4WDing - which also explains why she would jump start with the negative cable to the engine but not with the negative to the battery. This was easily fixed with a new cable and we were up & going again.
|1. Undo the negative battery
terminal or you will easily short ciruit things since you will be undoing
a cable which is directly connected to the positive battery terminal. Unbolt
the fuel filter from its bracket and unplug its cable. Leave the fuel hoses
on – just move it forward out of the way.
|2. The starter motor is on
the left rear of the motor (when facing forward), behind & underneath
the exhaust pipes. Unbolt the main thick positive power cable (black with
red stripe) and the solenoid cable plug (cable with “37” flag
in photo – it’s quite difficult to unplug.
|3. This view is from under
the wheel arch. The starter is fastened by two 17mm bolts. The lower bolt
is fastened by a nut and is not too difficult to remove, working through
the wheel arch. The upper bolt screws into a thread in the alternator housing.
See next steps.
|4. The upper
bolt is difficult to access since it faces backwards towards the gearbox.
I managed it with this very extended 1/2” driver with a universal
joint and 17mm socket at the end.
|5. It’s difficult to
just get the socket onto the bolt since you can’t even see it. I attached
the socket from the engine compartment (by feel) and then crawled underneath
the car and threaded the rest of the assembly through the gap between the
body and the gearbox and attached it to the socket. It takes 5 min just
to get there so don’t drop it now! Now unscrew the bolt. It would
probably help to have someone hold the starter up while unbolting it as
it gets looser.
|6. Now pull the
starter out – simple, just like giving birth…
|7. View from
above. You can see the bolt that the large power cable attaches to. This
photo was taken AFTER the electrician cleaned it. When I pulled it out it
was probably the blackest, dirtiest, greasiest car part I ever laid my hands
on… the photos here are actually of the refitting.
|8. View from below. You can
see the large cable that goes from the solenoid to the motor on the right.
I believe this switches on the motor once the solenoid has extended and
the gear is engaged with the engine. I should probably replace that rubber
|9. View of gear. You can
see that the upper bolt hole is smaller because it is threaded.
|10. Refitting is the reverse of removal.|