[jaaquo]

hi i have a mk1 02 focus tdci, and when ever i start the car, even from cold the radiator fan starts going. it does however switch off when the key is taken out of the ignition barrell.

i want to get it working properly cause it takes forever for the engine to warm up to its running temp, and therefore in the cold winter months i have to sit in the car for ages freezing my knackers off waiting for warm air!!

any ideas on what this could be would be fantastic

thanks in advance

 

[firelink74]

sounds like a short in the fan sensor.

 

[whynotthinkwhynot]

Have you traced down the wiring to see if anyone has been in there modifying the car? Do you have an electrical tester? Even if you don't, you can swap relays to see if that will tell you anything. Look in your owner's manual, and find the relays that operate the cooling fan. Now you'll notice that there are other relays of the same type and size. Find one on some other circuit, headlamps for example, that you can verify the operation of the relay. Now swap that with your cooling fan relay. If the lights come on and stay on, then you know it's a relay. If the lights work properly, then it could be a wiring problem, and you'll need an electrical tester to figure that out. In this case, you can start physically tracing the harness from the fans to the relay box, and you might be able to see some physical damage. Another possibility is that engine might use 2 different coolant temp sensors- one for the gauge, and one for the computer. I don't have wiring information, nor knowledge of the TDCI engine because they don't sell those in the US, so you'll be on your own there unless someone else pipes in.

Do you happen to have a check engine light?

 

[jaaquo]

i dont have a check engine light as far as i am aware, i shall look into the relays and can get hold of a multimeter at work, will let you know what the result is if i ever find time to figure it out!

thanks for your help so far

 

[sailor]

Agreed, sounds like a relay that "welded' itself in the "on" position...

Just pulling the relay would answer THAT question....

Luck!

 

[a_2000_se]

...... it takes forever for the engine to warm up to its running temp.......

You may have two problems :

One obviously is the constant fans but another may be a thermostat that is either stuck open or missing. How long have you owned the car?

The fans won't cool the engine much but they do cool the coolant. The thermostat functioning properly should warm the engine up quickly.

 

[nilskje]

Try switctcing the AC off & see if the fan stops..

 

[Dodgezilla]

That was gonna be my suggestion. I've noticed that if I start my car with the A/C on the fan automatically comes on. It may do the same if you always have the heat selector in the Defrost position. This would be the simple solution.