Fiesta heater

[tuftybri]

Anyone any ideas on why my car heater works ok sometimes but randomly goes off and just blows cold air for a while before returning to normal operation again?

[Count-A-Strong]

Loose electrical connection somewhere. Possibly.

[tuftybri]

Ok thanks Count-A-Strong, I'll look into it

[jake-the-peg]

Depends on the age but a lot of fiestas have a really dodgy valve arrangement that controlls coolant into the heater matrix.

It works on a kind of rapdly opening and closing gate controlled by the heater controls and is notorious for playing up.

It's located centrally on the top of the bulkhead with two pipes going in. It's not difficult to replace and most scrap yards will keep them because as I say they do go wrong. However the plastic tubes that the pipes connect on to become brittle over the years and can easilly break so you need to be very careful taking them off.

http://www.google.co....QwBA&biw=1280&bih=832

[AlBags]

Yep ..
Replace heater control valve. All will be well.