306 cooling fans

hi there

i was wondering if anyone can tell me what mite be wrong with my
cooling fans as they dont seem to be working when the engine is hot
and showing "STOP" light and the temprature gauge is over 90

my car is a 1994 peugeot 306 turbo diesel

many thanks :wink:

 

I don't know, but if you are getting heat out of the heater you can
use that as an emergency radiator. Run it full blast with the windows
open, unless you want to simulate Australian weather.

 

the stoplight sign is if you got WATER IN YOUR DIESEL so drain the water
out of your diesel by undoing your drain plug on your filter
houseing.the fan will not run at 90c its got to go a little bit higher
than that..

 

It is over 90. The only times I have seen the stop light (other than
switch on) are when the brakes have had a problem, or a lack of water
in the radiator leading to overheating.

I don't think there is any connection between the water in diesel
sensor and the stoplight.

 

Nah, the stop light is also for over temp. I had a similar problem with the
bitron sensor in my Xantia. It would give me an overtemp warning and a stop
light even though all was fine.

In the case of the OP I reckon having a look at the thermal switch that
controls the fans and or the wiring to the fans. Try putting 12V onto the
fan if you can and see if that gets it going. Short out the thermal switch
and see what that does.

 

Phil Cook wrote:

There was not on my old 306. The sensor was faulty it sometimes came on
even thought there was never any water in the filter. The stop light never
came on at the same time.

Pete

 

The STOP lamp is illuminated for a number of reasons one is when you have no
cooling.

This site shows an explanation of how the dual fan system works for cooling
http://www.peugeotlogic.com/workshop/wshtml/electric/ac306/coolfan2/fanop1.h


I have a 1998 406 1.9TD with air con and had the same problem. This uses a
bitrol system to control the 2 fans. The system is switched on by the brown
thermostat of the three on the engine. This then switches a changeover
relay and 2 other relays to either give slow speed both fans in series or
fast both fans in parallel. These relays are located under the badge on the
grill.

Sounds as though you have one of your cooling fans not working.
At about 80C they should come on in series both working at slow speed. Also
if air con
is switched on.
At 90 C they should both come on at high speed. These are controlled by 3
fan relays sited behind the rad grill under a cover, check here first for
dirty contacts or failed relay. The next possibility is a us
fan motor, faulty wiring or faulty earth. There are two 40 an fuses in the
engine bay that feed the fans one for each.

Car temperature gauges are notoriously bad at providing the correct
temperature reading. You can only be sure of the gauge reading if you check
the water with a second temperature gauge.
The thermostat opens at 83 C.
The fans are controlled from an electrical system
Both fans operate in series at 96 C (slow)
Both fans operate in parallel at 118 C (Fast)
To check the fans do both work, with the engine switched on remove the brown
plug on the thermostat housing. After a few seconds both fans should come on
at high speed.
If your engine cools rapidly after reaching 90+ I would not worry.
Water in a radiator is pressurised to lower its boiling point. If you have a
leak in the cooling system it will affect the cooling system efficiency and
lower the boiling point of the coolant.

 

I forgot to say that the control unit switches the earth side of the relays
to operate no the battery positive as you may expect.
Mike

 

The stop light indicates a range of faults normally lighting at the same
time as another warning. I've never seen an exhaustive list though.

Ours (petrol 306) seems to come on almost as soon as the engine warms up
with no other lights, and the temp indicator is sensible for the rest of
a 200 miles journey. The fan runs on even after a short journey (e.g. 4
feet today!) even in cold weather, so presumably a dodgy temp
sensor/connection to temp sensor (I suspect the latter in our case).
Doesn't always mean a serious fault, anyway and often cooling related.

Chris

 

The same happens on my HDI partner van , it can be running for about one
minute and the temperature gauge will, on occasion, go right round into the
red which sets off the stop light flashing and a beeper, this lasts for
about 20 seconds and then all goes back to normal.

GGJ

 

Chris
Could be you have the demister on, this uses the air con for dry air and
therefore the cooling fans are switched on.
Mike

 

Hi Mike,
no, I tend to leave the air set on windscreen and low fan, and sometimes
(?) have to turn off the aircon as it turns itself on when you start up.
Seems to need a regas anyway so I'll get the thermostat checked at the
same time in spring.

Chris

 

Chris

That is the reason your radiator cooling fans are running. When the controls
are set to screen, the air con is switched on to provide dry air even though
it does not show on the control panel.

This is why in the winter to preserve the integrity of the air con fluid you
should use the screen setting .

Mike

 

The light shows sometimes though - I'm not sure why if it's lying when
it's off.

Do you mean that there's no way to have the air set to screen without
aircon - that's a stupid waste of fuel.

On the 406 (which sets the aircon and "auto" fan when it's cold) I let
it run aircon sometimes for this reason, but I'm not going to use all
the time.

Thanks for the tips.

Chris