Fiat Punto Active "04" Loss of Ignition, but starter turns over?

When I started my apprenticeship, many years ago, nearly all cars were fitted with a “dynamo & inertia type starter motor”.
Because some cars electrical systems had a “Positive Earth” system, these units had to be “Polarised” before starting the engine. This was to make sure the unit worked with the right polarity, for the cars electrical system.
The “older” guys I was working with called this, “excite the unit”. Eg;- have you excited the starter/dynamo before you start that car?
Using these thoughts, I tried this out;-
Using a circuit tester (the type that looks like a screwdriver with a wire on the end, Halfords @ £2.99 apiece), I placed the pointed probe end into the “live” feed on the back of the alternator, leaving the plug in place (still in the alternator). I then placed the other end of the tester (crocodile clip end) on to the Positive (+) terminal of the battery.
Hey Presto! Ignition circuit has now become live again. Leading me to now suspect the alternator was the problem. Have now replaced it, and ended all my Daughters fears about her “little baby”.
Many thanks to all you out there for your suggestions. I’m sure they made me think a lot harder, & come to the correct solution.
Bob.

Bob Kingham
April 2008

Hi jonathan, thanks for that, already checked that out. Not same setup as older fords/vauxhalls. No seperate multiplug, loom goes direct to rear of ignition switch, then splits in 2, with 2 mini-multi plugs. All ok there. Got me really stumped, Car serviced by main dealer whilst under warranty, now doing servicing myself, early retired mechanic. Passed on all my diagnostic tools etc to my Son, who now lives in NZ, only got small tool chest left, Sods Law!!!!!
Thanks anyway, Bob.

bobboss
April 2008

hi mate check igntion switch multi-plug on steering column area, multi- plug burns inside

jonathan
April 2008