hello!

i got a problem with my punto hgt '00 mk2 cooling fan

when my engine is running, after 10 seconds the fan starts spinning full-speed, it doesn't matter if the engine is cold or warm. but it does not run if only the ignition is on.

- tested temp-sensor in FES: shows normal temperature
- swapped relais against others
- tested relais with FES: everythings ok

i also got a fault code:

P1531 - air con relais or circuit faulty (i can't delete this error)

but my air con is working

can anyone help me please?

thanks and greets from switzerland

Pretty sure the fan is switched on the earth side of the circuit. Frayed earth lead contacting out?

hmm i don't think it's that, because the fan is only running with engine on, and it takes about 10s before it begins running. also i can check the fan with FES (when the key is in position MAR) and it begins running and stops after the check... it must be some electrical problem, something says to the ECU that the fan has to run, but i don't know what it is...

or did i understand you wrong? i'm not so good in english

P1531 - air con relais or circuit faulty (i can't delete this error)

Click to expand...

this is your major clue

the aircon circuit is all in series so if there is a fault the ECU can't tell where it is in the circuit

Fauly aircon system will default the radiator fan to on to protect the system. you'll need to make sure firstly that the system isn't over filled then turn your attention to the pressure sensors

I can only find "Climate Control, Open Circuit". So, my guess is that a fault with the air con side of the electrics is causing the engine rad fan to come on and stay on. "Open Circuit" might suggest an issue with the earth side.

okay thanks, that sounds plausible! i'll try to look at it sunday. does anybody know where i could find some wiring/circuit diagram of the air con?

A Haynes manual will help you out there

Ziggy

hey guys, i just exchanged the complete fuse box (20€ on ebay) and the problem seems to be gone.. no more ecu errors and fan is quiet (but still works when tested with obd). still have to keep an eye on it the next days.