1.4 auto wont start when hot, doesn't turn over, just clicks

As title my partners 2005 C3 1.4 sx auto/triptronic won't start when hot.

Car starts no problem when cold or cool but if you've been driving around for say 30 min or so it won't start again, the starter doesn't turn it just makes some sort of relay clicking, I've checked battery voltages and they seem ok as does terminals etc, I've plugged it into a normal diagnostic machine and no codes came up, I was thinking of putting it into Citroen to see if they can find any fault codes or high readings on any sensors etc

I've read up on here and other pages on the internet and can't find anything conclusive about a common fault, I see some people have problems with the Auto ecu but I gearbox works fine when driving and when trying to start it when warm it knows what gear it's in etc, it's just this starting when warm issue that's being a pain.

Any help would appreciated

Many thanks

Doug

Welcome to the forum justdug

justdug wrote:Car starts no problem when cold or cool but if you've been driving around for say 30 min or so it won't start again, the starter doesn't turn it just makes some sort of relay clicking, I've checked battery voltages and they seem ok as does terminals etc,

A poor connection to the starter circuit that is acceptable when cold but as it gets warm the resistance increases to an unacceptable level and the starter won't turn.

I would check by removing and cleaning the starter, earth and battery connections that are part of the starting system.

Then move on to the starter itself, you can get a price for a C3 starter motor from Euro Car Parts (here).

justdug wrote:I was thinking of putting it into Citroen to see if they can find any fault codes or high readings on any sensors etc

I don't think there will be relevant codes, if its the starter circuit.