FBH always running

I started the TD4 this morning and the outside temp was 13°c but the FBH still started. I'm sure Ive read somewhere its not supposed to run over 5°c. Ive looked through the forum and someone suggests it could be the ambient air temperature switch is stuck closed. Can someone tell me where I can find this switch ?

BTW I only drove about 2 miles on the school run but engine temp was reading the normal half way mark. Dunno if that makes any difference.

Many thanks in advance.

The temp sensor switch is located behind the bumper. I got to mine by cutting a flap in the mesh grill, so didnt take the bumper off. Once switch replaced, i just folded the flap back down. Can hardly tell.

The switch doesnt operate at exactly 5 degrees though, this is more of a guide. The heater may well come on above this, and, this is only my experience,will usually stay on beyond a 2 mile run, as it needs to reach a pre-set temp, then start its cool down cycle. Mine has stayed on beyond a six mile run, even though the coolant temp showed normal. It wasnt burning fuel by the end of the run though, just cooling down.

Hope this helps.

I has a simliar question and posted here (no real ansa) and here and got a good answer.

Mr K said:

I has a simliar question and posted here (no real ansa) and here and got a good answer.

Click to expand...

Still none the wiser :LMAO:

So is it normal to start up beyond 10°c ?
Did anyone elses FBH kick in yesterday even tho the outside temp was above 13°c ?

You'll find it won't be off until about March/ April. The air temp may be high(ish) but the block temp will still be low. Add in the wind chill and quite a basic sensor then what you have is quite normal.

mine has been running every day since begining of november when i got it working by resetting the ecu

Mine is running, although not for long, when very cold it would still be running after engine off but now I think it goes off when the engine reaches temp.

Didn't come on at all today.

Sounds normal then. Same here but was only on for a short bit. 70 mile run in 9 degrees got things hot enough for it not to be on for the return trip.