Technical Electrical weirdness after starter motor change

[Ginger34]

Agghh! Just replaced the starter motor on my Fiat Punto Mk 1 with a breakers unit (via eBay). It was a bit of a fiddle but went in okay. Reconnected everything...went to start the ignition and...

Switching to "I" on the ignition - I had dim dash warning lights and the speedo needle rose up to about 40 mph (but obviously the engine wasn't running).

Switching to "II" - the speedo needle fell to about 10, as did the warning lights in brightness, but no starting or sound from the starter motor.

I disconnected the battery, had a quick fiddle under the bonnet but couldn't see any issues. I'm certain that I've connected the starter motor connectors the right way around. The only problem I can think of from the fitting is that one of the connectors could be slightly loose - but surely that wouldn't cause the problem described.

Any ideas at all greatly appreciated...the car is on a random street a walk from my house, so it's a pain and I'm pretty desperate to get it sorted.

 

[fingers99]

Puzzling. Disconnect battery, check leads to starter (they need to be well on and damn tight as well as the right order). Replace battery connections -- good and tight. Try again.

If nothing try a single jumplead from battery negative to somewhere solid and metallic on the gearbox.

Get back.

 

[Ginger34]

Puzzling. Disconnect battery, check leads to starter (they need to be well on and damn tight as well as the right order). Replace battery connections -- good and tight. Try again.

If nothing try a single jumplead from battery negative to somewhere solid and metallic on the gearbox.

Get back.

Tried no. 1 - including polishing the contacts up and ensuring they are tight. Still the same symptoms. Just to be sure - there are only 3 connections - a large black cable with metal plate (connecting to battery) which goes to the large bolt furthest from the solenoid. A red cable with a O connector (leading from alternator) which connects to the smaller bolt. And a little spade connector which i think is involved with the ignition. I've made sure that's well squeezed on.

Going to borrow/buy some jump leads now to try your second tip. Thinking it could be an earthing issue, but don't think there's an earth strap to the starter?

Thanks

 

[Ginger34]

Starting to wonder if i've got the connectors the right way around!

Based on this picture...i've wired it up as follows:
Terminal B - to the battery - on my Punto it's a wire shrouded in ribbed plastic, going to a roughly 1 cm x 4cm metal plate with a hole in the end.

Terminal M - a thickish red wire connecting to a short flat O ring. If I follow this it connects to the alternator.

Terminal S is just the spade connector to the ignition.

I removed this ignition spade connector, and gave it a try (I was wondering whether a faulty connection here was causing the issue) but I then go no response from the car at all when turning the ignition.

 

[Ginger34]

Looking at the wiring diagram in my Haynes manual, and a few other posts for other starter motors, I think I might have got it wired wrong! It looks like both connectors go to the long bolt and the bolt with the braided wire connecting to the big solenoid is left well alone.

Uh oh....hope I haven't done any permanent damage....

 

[Noddy]

Did you try and jump? Speedo rising is normally an almost flat battery.

 

[varesecrazy]

Looking at the wiring diagram in my Haynes manual, and a few other posts for other starter motors, I think I might have got it wired wrong! It looks like both connectors go to the long bolt and the bolt with the braided wire connecting to the big solenoid is left well alone.

Uh oh....hope I haven't done any permanent damage....

I believe you are now correct..!!,
let us know if it now works o.k.,
Charlie

 

[Ginger34]

Did you try and jump? Speedo rising is normally an almost flat battery.

That's fantastic news Was starting to think that the batt might be a secondary issue, but couldn't work out why the needle was still flickering (even on rewiring).

Other evidence - a helpful passerby hooked up my battery to a booster unit - which he said wouldn't be enough to start it but enough to see if the battery is the issue. With that, got dash lights on again and a clunk from the starter.

Hot-footed it to buy a battery charger and it's now enjoying an overnight charge.

Fingers crossed, it'll whir into life tomorrow.