Technical Intermittent alternator fault.

[Chris legg]

In the last week my fiat 500 sport has been showing the battery warning light upon starting, the steering is stiff. I hooked it up to multiecuscan and it reported intermittent alternator fault. The strange thing is that if I turn ignition off then immediately restart the issue goes. I don't know what to check first. Any help would be great.

 

[ZaphodB]

Check all connections of engine earth strap, the conditon of the strap and all starter and alternator connections.

Also how old is the battery? (4 digit date code on it somewhere)

 

[John202020]

As above how old battery?

 

[GettinBetter]

In the last week my fiat 500 sport has been showing the battery warning light upon starting....

Temporarily add a jump lead from battery negative terminal, to a clean point on solid part of the engine. Costs virtually nothing, but if the fault goes you know, it's a bad earth.

Please post results.

 

[Chris legg]

Temporarily add a jump lead from battery negative terminal, to a clean point on solid part of the engine. Costs virtually nothing, but if the fault goes you know, it's a bad earth.

Please post results.

Thank you, I will try this tomorrow and post back.

 

[Chris legg]

Thank you, I will try this tomorrow and post back.

Right so it seems to have fixed it, so far! In general which end of the earth cable usually fails connection please? Many thanks indeed!

 

[GettinBetter]

Right so it seems to have fixed it, so far! In general which end of the earth cable usually fails connection please? Many thanks indeed!

I replaced the section from chassis to gearbox, and also the section from battery to chassis (under battery tray) but it only fixed it for a few months. In the end I added a new additional earth cable.

 

[ZaphodB]

Right so it seems to have fixed it, so far! In general which end of the earth cable usually fails connection please? Many thanks indeed!

The thing to remember is to prevent (as best you can with various methods) air getting to:

One: any connection surfaces - clean up (brighten up) both the surface you're clamping to and any ring terminals on that connection, then once tightened up, you can smear it with grease or vaseline.
Two: any of the internal copper strands - with a new cable get a sheathed one (not exposed braid) and make sure the ring terminals have heatshrink attached (preferably adhesive lined) to cover up any little bit of exposed copper between the end of the ferrule of the terminal and where the insulation starts again.

 

[Chris legg]

Right so it seems to have fixed it, so far! In general which end of the earth cable usually fails connection please? Many thanks indeed!

 

[Chris legg]

I spoke too soon, I thoroughly cleaned all terminals, then buzzed it out with a multimeter, whilst flexing it, all good, I made an extra permanent connection from a bolt on the engine to the negative battery terminal and started the car, same issue, battery light stays on. Turn off then immediately start and it remedies itself! I plugged it in to multiecuscan and the fault was intermittent alternator error, I'm stumped what to check next.

 

[GettinBetter]

I spoke too soon, I thoroughly cleaned all terminals, then buzzed it out with a multimeter, whilst flexing it, all good, I made an extra permanent connection from a bolt on the engine to the negative battery terminal and started the car, same issue, battery light stays on. Turn off then immediately start and it remedies itself! I plugged it in to multiecuscan and the fault was intermittent alternator error, I'm stumped what to check next.

Thats a pain, have you got some pics of your new cable, including terminations (both ends)?