Strange fan behaviour
Discussion
So, last week determined the horn on the Chimaera was not working. Bit of a problem as it was booked in for an MOT on Saturday morning.
No problem, diagnostic tools out, figured out eventually that the fault lies somewhere within the fuse box circuitry and the fan relay is not getting a positive feed (on the low current side), which it is supposed to get presumably fed from internally, as there is no feed wire for this.
No problems there, I pull the relay, put the horn feed and earth wires, and the low current earth directly on to the relay, then add an ignition feed directly from a spare terminal on the fuse box to the relay low current feed.
Horn works, superb......
Now everything is working perfectly, take it for an MOT.
On the ramp getting emissions test and the engine boils over. Too much of a coincidence, I must have dislodged the relay, Start her up again and all is fine.
Driving home in traffic engine gets hot, cycle ignition and the fans cut in.
Does it reliably ever time, Cold start, warm ups no fans, engine overheats. Cycle ignition and fans cut in.
Seems like the fans don't work when the ignition is first switched on.
Can anyone help? Does the circuit board have some kind of internal latching?
It was working absolutely fine before I did the horn the fans were on most of the time!
No problem, diagnostic tools out, figured out eventually that the fault lies somewhere within the fuse box circuitry and the fan relay is not getting a positive feed (on the low current side), which it is supposed to get presumably fed from internally, as there is no feed wire for this.
No problems there, I pull the relay, put the horn feed and earth wires, and the low current earth directly on to the relay, then add an ignition feed directly from a spare terminal on the fuse box to the relay low current feed.
Horn works, superb......
Now everything is working perfectly, take it for an MOT.
On the ramp getting emissions test and the engine boils over. Too much of a coincidence, I must have dislodged the relay, Start her up again and all is fine.
Driving home in traffic engine gets hot, cycle ignition and the fans cut in.
Does it reliably ever time, Cold start, warm ups no fans, engine overheats. Cycle ignition and fans cut in.
Seems like the fans don't work when the ignition is first switched on.
Can anyone help? Does the circuit board have some kind of internal latching?
It was working absolutely fine before I did the horn the fans were on most of the time!
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