Where to start with non starting cooling fan? 2.7hdi

[nickyg]

Hello all,

I am quite shaky with the electrical side of maintainence. Will have a go at most mechanical issues, but electrics are a minefield to me!

On my 2.7hdi C6 the twin cooling fan is not working. I it would likely be the same fan as on C5 and 407 2.7hdis, and I suppose cooling fan issues may be relatively universal.

I have had coolant leak issues in the past, now remedied. It was the jet plane like whir of the fans that alerted me to a coolant leak, working to compensate (there is no low level coolant warning sensor on these £40k+ cars!). So I know they worked not so long ago.

I have tried watching as the car idles to to the requisite temperatures, but no kick in. I have tried switching the air conditioning to force it on, but it doesn't come on. I do hear a relay click upon switching on the air conditioning, though. I'm not sure if that makes the diagnosis easier or murkier!

From what I've tried to gather I should be testing the motors with 12v, then relays, fuses and wiring circuits. I am not at all experienced in this area of vehicle troubleshooting. Any thoughts on where I should be focusing would be much appreciated.

[SaabC5]

Best thing to do is get the car on a Lexia to diagnose where the fault lies. Suspect the temp sender unit which is normally screwed into the radiator housing before the actual fan unit. You can test the fan by unplugging it and putting 12v through the positive/negative terminals just to confirm its good. Does the C6 have just one fan for both cooling and climate control, a lot of larger cars have seperate fans now.

[nickyg]

Thank you for the reply saabc5. I'm pretty sure the the twin cooling fans in front of the radiator are the only ones in there. I've been in and around the engine bay quite a bit over the years, and I don't recall coming across (or hearing talk of) any other fan unit (aside from interior heater fans/blowers , of course).

I will get my lexia dusted off and tried out again, though am pretty pessimistic about my ability to discern readings from certain sensors being right or wrong!

The temperature gauge (digital, on screen) seems to be behaving normally. :-\

[Hell Razor5543]

As yours is an HDi, it is possible you could test the fans via the Lexia. I did so on Gracie, and she is a Xantia HDi. However, when testing on low speed both fans turned, but on high just one fan turned. Apparently this is normal (on the Lexia test, anyway!).

[SaabC5]

Cars with 2 fans normally have one fan for radiator cooling and the other for the air con cooling. Its not unusual (Tom Jones) to have them both come on in extreme temp conditions when one fan isn't sufficient.