Jeanneau 39DS Engine Compartment Fan

[mrkeith]

This fan is not working- I have checked the fan which is OK (it has been operational) but their is no power in the cables to the fan position. The manual appears to show a fuse box next to the engine battery but when I look, it is not there. Can anyone please assist? I am convinced that the answer to the problem is very simple - all electrical connections appear clean and secure. Could there be another reason for it not working when the engine is turned on?

Many thanks

mrKeith

[Don Reaves]

In my SO35, the fan is controlled by a thermostat. The fan turns on only if the engine compartment is quite warm.

I recall seeing another thread where this is discussed, and I'm pretty sure that not all the SOs are wired the same as my SO35, so this might not apply to your boat.

Don

[sitara]

Hi,
Check this from the hints and tips page www.jeanneau-owners.com/hintsandtips/variablefan.html It describes the replacement of the thermostat that was fitted to the SO 37, My SO 36i did not have this switch and the bilge fan was on all the time and quite noisy. I have just done the replacement shown in the hints and tips and it works a treat with the fan only coming on when the engine compartment heats up.

[rene460]

Hi mrkeith,

The wiring diagram for my SO30i also shows the engine compartment fan supply through the 7.5 A fuse next to the batteries (in with the battery charger etc) as you have described and then through the engine control switch, another location for a potential poor connection.  There are more details on this switch wiring in the Yanmar manual and presumably in your engine mfrs manual if you have a different one.  The fan is on whenever the engine switch is on as others have described.  I suspect that this is the standard factory arrangement for many models.  It is a bit noisy though I do not find it an issue when the engine is running.  Then my wife says I need to have my hearing checked - there are often more than one explanation for such differences of opinion.

It is possible that the fuse block for some reason is in a different location on your boat.  Alternatively, if it is not a new boat, a previous owner may have installed a temperature switch per the hint and tips as described above, which would explain the lack of power to the fan when the engine compartment is cool.  In this case some more detective work and wire tracing will be required to find and check out the modification.  

In case the modification resulted in the fuse removal, I would be inclined to reinstall a fuse in the circuit once you have found the correct wire, as part of the solution to the issue.

Rene460

[mrkeith]

Thank you all for responding so quickly. All comments have been very useful.

Rene- the boat was bought new just over 5 years ago. I located the fuse box near the charger unit but I was confused when I read jeanneau's wiring diagram as there appeared to be a second fuse box the other side of the engine battery, in a more central position under the rear bunk. This I cannot find, maybe for obvious reasons!

Incidentally I did contact Jeanneau who responded by return but did not really answer my queries.


The fuse you mention appears ok but I will now check and replace with new. Otherwise I understand that you think it must be a wiring fault?

many thanks

Keith 

[rene460]

Hi Keith,

In your first post you said you had checked the fan and it was ok but there is no power in the cables to the fan position.

Also it was working so it was originally wired correctly whether with a thermostat (not shown on your wiring diagram?) or without (as seems to be the standard factory wiring).

My thinking is that no power in the cables implies a "break" in the wiring.  Likely locations for this break start with the fuse, followed by a faulty switch (in this case I believe the only switch is in the engine panel) or a loose or corroded (eg if it has been subject to water dripping) connector.  It is also possible that a wire could have its insulation worn through due to vibration against some part of the boat possibly leading to a short.  I would consider this least likely and in any case it would be expected to cause a blown fuse.  Wiring could also have been in intentionally modified if you have recently had other electrical work done.

The trick is to find how far the voltage goes.  I use a long piece of wire with a clip on each end so I can use the volt meter further from the battery than the meter's test leads allow.  Don't overlook the possibility of the problem being in the negative lead.

Incidentally if you have not actually tested the fan since it stopped working, you can test it using some temporary connections and two 6V lantern batteries in series.  If it does not run, it could be brushes which may be replaceable, however you would then expect voltage in the wiring at the fan when the engine switch is in the on position. 

I hope I have not bored you with all of this but you seem to have been looking for more explanation.

rene460

[ianqv]

As already mentioned above.... this fixed mine: www.jeanneau-owners.com/hintsandtips/variablefan.html