Fiesta car heater

This heaters turned out to be a little bit of a problem just thought you might be interested in the result.

The symptoms were "not very hot cab heater" . First thing I did was clean out the pollen filter.

Now I have airflow but it wasn't very hot still. So I now attacked the heating system. Obvious place to start, as the car was a 02 replace the thermostat.

This had the effect of reducing the effects of the heater, giving the symptoms of an airlock. The heater would get lukewarm, and then go cold. I attempted to bleed the airlock. As I tried to pull the hose off the heater control valve, the pipe came with it, the plastic of the heater control valve pipe was like eggshell. So do in due course a replacement was purchased. I took notice of all the warnings on the Internet about not using the very cheap valve's from eBay, etc and on Christmas Eve I purchased a Euro car parts heater control valve. This was about 7 pounds cheaper than the one they sell as OEM.

Fitted the new valve, checked operation, job done. Nice and simple. No airlocks great.

10 days later Wife complains "can't turn heater off". I check connections, and heater control works perfectly. Do a trip of 25 miles about halfway there the car heater really heats up and we can't turn the heat off!

When we get to where we are going I check the connections on the heater control valve. I touch the body of the solenoid with my index finger and it hurts me. So I touch it again, it's bloody hot! I Spit on my finger and touch the solenoid body and it bubbles and spits as it boils. The car is now left for an hour, I set the heater control to mid way and it stays okay on the way home. It would appear that the heater controll valve solenoid is jamming open and overheating through the current trying to close it.

If I can find the receipt I will take it back and get the OEM one and pay the difference. Meanwhile I have an index finger with shiny skin.

Anybody else had this problem with this control?

Gary

Reply to
Gary
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It would surprise me to learn there was anything as complex as a solenoid in the heater of my Fiesta...

Reply to
Andrew Gabriel

Then you will be suitably surprised. The heater control valve on KA Fiesta and others is a electrical control and the mushroom shaped valve is operated by a type of solenoid. the valve is 'normally open' and the solenoid pulls it closed. the amount dependant on the current through the solenoid

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mins is the operation bit.

Reply to
Gary

Mine's the other way round - won't turn on - a right hooter in this weather!

Now on the second one - replace under warrantee (only just got the car used and garage said 3 months we'll fix stuff). They replaced 'automatically' as "always failing". due in tomorrow for another go :-(

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Reply to
The Nomad

Hang on a moment, so the solonoide presumably works against a spring and it gradually pulls it closed? Maybe its meant to get hot?

Seems an odd way to go, I'd have thought a cheap motorised valve would have been more reliable.

Brian

Reply to
Brian Gaff

I think that was the problem with the SWMBO'd Fiesta.

Yep a "known fault". Uses a slow PWM waveform to regulate how much hot water gets fed to the heater matrix. Never sorted out the problem on SWMBO'd car as she decided that taking a flying leap over a wall and landing on a side in field was a good way to get a new car...

Reply to
Dave Liquorice

That (almost) is how come I've got this one :-(

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Reply to
The Nomad

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