Cooling Fan Not Stopping
Moderator: RichardW
Cooling Fan Not Stopping
Yesterday the Xantia overheated due to the top big coolant hose popping off on the motorway, it lost all the coolant. I sorted this out yesterday evening. When I got home from work tonight (40 Miles) the front fan was still going when I got out of the car. Some 4 hours later I realised that my alarm was going off. When I went to check it, the fan was still going?? and the battery is now completely flat [:(] Has the overheating damaged any fan sensors or is there any way of finding out what the problem/cause is once I have charged the battery? I would appreciate your thoughts.
OK tony -
Then something is stuck on, continously feeding the fans.
Fuse F3 in enegine bay fuse box feeds the fan, you can remove this while you charge the battery.
You should have a fan thermo contact located in the radiator. You can reckon it by having heavy gauge wires running to/fro. Try disconnecting the connector, and see if it's a 2pole or 3pole connector.
case 1 : 2pole connector : you have the very simple on/off control of the fan. This is also denoted by the fan running at high speed with a slight roaring.
cas 2 : 3pole connector : you have a 2stage (2speed) control of the fan. If fan is running at stage 1, it would only whisper.
In case 1, the only thing that can stuck on to feed the fan, is the thermoswitch itself in the radiator. Check thermoswitch with an ohm meter, to exclude a direct short in the cabling.
In case 2, you would have a relay, which could have welded contacts, setting the fan on continously at high speed, or still the thermoswitch could fail as above, setting the relay on continuosly.
If the fan is contnously on at lo speed, it's the the thermoswitch stuck on. Check as above.
With cold radiator, any pins on the thermoswitch should read high ohms.
BTW : Any chance the thermoswitch/connector was wetted, even a relay in that area, when you first had the problem ?
Then something is stuck on, continously feeding the fans.
Fuse F3 in enegine bay fuse box feeds the fan, you can remove this while you charge the battery.
You should have a fan thermo contact located in the radiator. You can reckon it by having heavy gauge wires running to/fro. Try disconnecting the connector, and see if it's a 2pole or 3pole connector.
case 1 : 2pole connector : you have the very simple on/off control of the fan. This is also denoted by the fan running at high speed with a slight roaring.
cas 2 : 3pole connector : you have a 2stage (2speed) control of the fan. If fan is running at stage 1, it would only whisper.
In case 1, the only thing that can stuck on to feed the fan, is the thermoswitch itself in the radiator. Check thermoswitch with an ohm meter, to exclude a direct short in the cabling.
In case 2, you would have a relay, which could have welded contacts, setting the fan on continously at high speed, or still the thermoswitch could fail as above, setting the relay on continuosly.
If the fan is contnously on at lo speed, it's the the thermoswitch stuck on. Check as above.
With cold radiator, any pins on the thermoswitch should read high ohms.
BTW : Any chance the thermoswitch/connector was wetted, even a relay in that area, when you first had the problem ?
The conncector was wetted when the first problem occured (2pole connector). What I find strange is that it got me to work ok in the morning and it happened after I got home in the evening, which lead me to believe that it can't be a direct short from the previous event. I'll borrow an ohm meter once the batt is charged and see what results I get. Thanks again.
I'm going to pick up a new connector on Wednesday and hopefully that'll do the job. The fan is draining the battery at +11.5 constantly. Until I sort it I'll just have to remember to connect it when I use the car and disconnect when I dont! With the fan going continuously the temp don't go above 70, even in a traffic jam! Thanks Anders.