Cooling Fan runs constantly

[horacemorris]

Hi Guys,
I'm a newbie on this forum. Can anyone help with a small problem.
The fan on my 05 FZ6 has begun to run constantly as soon as the engine runs, even from cold. It's only just begun to happen recently and during a very wet spell. I'm wondering if this could be caused by water entering a connection and shorting something out. Before I start to pull things apart, has anyone else suffered this prob.

Thanks in advance and well done on the website/forum

 

[Fred]

What does the temperature gauge on your dashboard say? It it's showing that the engine is hot even when it's cold, then you probably need to replace the temperature sensor.

If the temperature gauge displays the correct temperatures, then the cooling fan relay is probably stuck or as you guessed, full of water.

 

[reiobard]

well, i would say that it is better on all the time rather than never turning on. I also think it sounds like a short.

 

[horacemorris]

Temperature gauge shows normal running temperature (about half way up the scale after about fifteen mins running in traffic and the bottom bar on the rev counter stops flashing around the same time).
As i said before it's straight after a really sustained wet period here in Blighty.
Looks like WD40 time!

 

[madmanmaigret]

thats what I would say.........WD-40 time.

 

[Fred]

Looks like WD40 time!

FINALLY! Somebody is using WD-40 for its intended purpose!

I can die happy now.

 

[wolfc70]

FINALLY! Somebody is using WD-40 for its intended purpose!

I can die happy now.

Haha, that is a first.

As to the fan staying on all the time, I would check the fan relay. This exact same thing happened happened on my car, the relay got stuck closed causing the fan to run constantly.

 

[FZyLarry]

Temperature gauge shows normal running temperature (about half way up the scale after about fifteen mins running in traffic and the bottom bar on the rev counter stops flashing around the same time).
As i said before it's straight after a really sustained wet period here in Blighty.
Looks like WD40 time!

I'll try to remember to watch tomorrow, but I think my blinking rev indicator stops blinking as soon as I get one bar on the temp gauge.

 

[horacemorris]

Thanks for those of you who took the time to reply.
WD40 didnt do the trick, my next plan is to try the fan relay as suggested, but without a Haynes, i'm not sure where it is. Is there also a temperature control sensor too?
I'm really fed up with this now because i've done a lot of short trips lately and the battery is getting hammered with the fan running all the time as well as all the other electrics.

 

[alanrim]

I'm really fed up with this now because i've done a lot of short trips lately and the battery is getting hammered with the fan running all the time as well as all the other electrics.

It is also bad for the engine as it will struggle to make optimum temperature with the fan running all the time.

No idea where the thermostat is on the FZ so can't help with that, but I can wave at you from just over the border in Sheff :wav:

If you get really stuck I could probably nip and have a look at the weekend, see if we can sort it.

 

[fudge_FZ6]

I know its to late but you should NOT use WD-40 on any electrical parts. Reason it leaves a film that will cause a short. use a contact cleaner type solvent it evaporates fast and is silicon base so it won't conduct electricity. use the search on here somebody has posted before a link to download the service manual.

 

[fudge_FZ6]

just reading more of the service manual and in the trouble shooting part under over cooling it say that the thermostat is stuck open.

 

[Data]

The parts and wiring diagram is available on the Yamaha website. Having replaced the fan assembly after a rock got stuck between it and the radiator, I can assure you that it is not something you want to dig into if you have a choice. Is the bike still under warranty?

 

[horacemorris]

HI,
Thanks to people posting useful suggestions, i've been able to track this down to a faulty fan motor relay as the temperature gauge is working ok and showing the correct temperature so therefore the thermostat/temperature sensor must be working ok.
As it's bloody freezing at the moment, i've taken the fuse out of the circuit to give the battery an easier time till i can get a new relay and yes, i know i shouldn't, but needs must!
I can't find a replacement online so it's off the the dealer i guess, anyone got an idea of price?
On a car, this would be about a fiver, but as with most things motorcycle it'll probably be ten times that!
I've also noticed that the headlight relay is the same model, could it be that they're interchangeable and could be used to test the circuit by swapping relays?
Thanks again to all who have replied to my post

 

[horacemorris]

No luck with this as yet, tried swapping the relay with the headlight relay (it's the same type) to no avail.
Any more suggestions?

 

[alanrim]

No luck with this as yet, tried swapping the relay with the headlight relay (it's the same type) to no avail.
Any more suggestions?

Looking at the wiring diagram would suggest that if the temperature is displaying correctly then it looks like the output from the ECU has gone faulty.

 

[horacemorris]

Just to let people know that i've now sorted this problem.
The wiring to the sensor was really badly kinked and was shorting out inside the sleeving, after repairing this, re-routing it and cleaning the plug on the end with contact cleaner, it now works fine.
Thanks to those who offered helpful suggestions.