Lights and wipers work but engine won’t turn over?

Hello C3Owners,
Nice to find you all here!
We’re having a bit of fun with our old lady.
We gave the battery a full charge as it didn’t start after Christmas and it started ok- first time.
But the very next day, it didn’t turn over again - lights and wipers both came on though? We put it back on the charger as we needed to make a trip and it registered ‘maintaining’ on the charger which I thought made sense of the lights etc working.
It started again first time, but since then it is repeating this problem.
The battery is supposed to be new just last year going into lockdown... is it some kind of electrical fault with the ignition? Does anyone have any experience of this?
Thanks In advance for any advice, and as I said, really great to find you all here

Meehano wrote: ↑Tue Mar 09, 2021 9:40 am Hello C3Owners,
Nice to find you all here!
We’re having a bit of fun with our old lady.
We gave the battery a full charge as it didn’t start after Christmas and it started ok- first time.
But the very next day, it didn’t turn over again - lights and wipers both came on though? We put it back on the charger as we needed to make a trip and it registered ‘maintaining’ on the charger which I thought made sense of the lights etc working.
It started again first time, but since then it is repeating this problem.
The battery is supposed to be new just last year going into lockdown... is it some kind of electrical fault with the ignition? Does anyone have any experience of this?
Thanks In advance for any advice, and as I said, really great to find you all here

Hello

A new battery can be damaged by a deep discharge (the alarm over lockdown) then fail in freezing conditions.

Your battery may only hold enough to start once, do the lights and wipers.

The drive after starting may not be enough to refill the battery and only a off car charge can put enough in to start it, but then the cycle continues.

there is a battery tester like this one here that puts a load on the battery to see how much power it can store, rather than just check the voltage. This sort of test can better diagnose the battery load capabilities in these sort of starting situations.


My suggestion would to test the battery with a load tester to take it somewhere that has one to prove/disprove the battery before going any further.

The amount of current required the turn the engine over dwarfs the amount required to run other pieces of equipment on the car. So the fact that the lights and wipers work does not tell us much about the status of the battery.

A very quick-N-dirty check is to start the car with the head lights on. If the headlights die, then it's your battery.

Yes, as Arfur said short trips may not recharge the battery enough.

You said; "The battery is supposed to be new". What does that mean? If you don't know how old the battery is then it's back on the suspect list.

It is unlikely to be the alternator or other parts of the charging system as the car appears to run fine after starting.

I don't have access to the circuit diagrams here but if I recall, the starter solenoid on a manual car is driven straight from the ignition key switch. Could it be the switch, could it be the starter? Maybe, but unlikely, given the symptoms you describe.