Rad Fans Not Working

[v8s4me]

My neighbour has asked me to look at his straight 6 Cerb because the rad fans won’t cut in. I’m not familiar with Cerb’s so can anyone tell me where the fuse/relay box is and which fuse/relay it is? Is the otter switch accessible, and where do I find it? Is this a common fault or is it a matter of checking it all through step by step? Steve Heath doesn’t seem to do a “bible” for the Cerb, so what’s the alternmative? Many thanks in advance.

[Ireland]

First thing to check is the spade connections at the fans themselves.

If they corrode they can prevent the fans from cutting in (it did on mine and it's fine since I cleaned the contacts).

The ECU brings on the fans so you'll need to plug in a laptop with diagnostics software if that doesn't work.

There isn't a Cerb bible.

[C3BER]

Could be a faulty sensor. I know how to do it but I'm not sure on the correct names but you can test if the fans are working by pulling the sensor near the radiator bottom passenger side. Does the horn work as it's on the same relay as the fans if I recall.

[Steve_T]

If you get the F panel off the car you'll see the water temp sender in one of the water rails. If you unclip the connector to temp sender and start the engine the fans should come. The ECU sees the connection to the temp sender has gone open circuit, and switches the fans on as a safety precaution. If they don't come on you need to check the connectors, relays and fuses. If they do you need to replace the temp sender. Reconnect the temp sender when you're done.

[v8s4me]

Where/what is it “F” panel? Sorry if this is a stupid question but I’m off the ‘S’ Forum and have no knowledge of Cerbs. Where will I find the fuse/relay box and how will I know which fuse and relay to test? Any photos would be much appreciated. Any idea what the resistance of a working temp sender should be?

[Steve_T]

Sorry, did't want to sound patronising in my previous post. The F panel is just the front cover in between the engine and the radiator. The fuses and relays are in the boot behind a cover on the right hand side that's held on with velcro. I don't know which fuse does what, I just tend to check the all of them in sequence with a test meter.

[C3BER]

Not sure the 6 has the F1.

[natben]

Yea the Six has the F panel, you need to remove the air intake box above the radiator and the concertinad pipe between that and the airbox, then undo the 2 bolts on top of the radiator and then 4 allen key type bolts down the inside of each wing. Remove this then check the spade connectors(2 of) at the bottom of the radiator behind the oil tank, give them a clean.
Still no joy, look below the air box (big black thing beside engine) below this behind the alternator you will find the water temp sensor pluged into the engine (one black wire near the top of the engine but below the airbox)remove and start the engine fans should come on automatically, if not, start looking at fuses!!