Ford KA, KA2, KA3 (1996 - 2008) - 04 1.6 Different heater problem.

Honest John Back Room » Technical matters
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Sat 9 May 2009 08:16
04 1.6 Different heater problem. - goooba769
Right then my wifes sportka had a problem where the heater constantly gave out hot air regardless of temp dial position. Now after a bit of digging found it is most likely the heater valve so I purchased one and fitted it. Now I tested both valves when switching them and the old one did nothing but the new one opened so all fine there. Now its still chucking out hot air so I need some help. Now I have found there is a constant 12v supply going to the valve regardless of what position the dial is in(Im fairly sure this is not right) so all I can assume is the valve is open all the time so the hot water is going around heater. Now I have removed the heater control panel and when disconnected the 12v supply goes so Im assuming there is no wiring damage and all I can think of is the control panel is faulty? Can anyone give me some advice if possible?

Edited by Pugugly on 10/05/2009 at 23:29

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Sat 9 May 2009 08:30
04 1.6 Different heater problem HELP PLEASE - mfarrow
If the valve is a brand new one from Ford, then it's probable that the control panel is faulty. The output voltage is however switched, so a normal multimeter will only pick up the 12V peak of the wave - you need an oscilloscope to see the rest.
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Sat 9 May 2009 09:30
04 1.6 Different heater problem HELP PLEASE - goooba769
Well, it wasn?t from ford but I bought it off the internet. Although, the new one is operating as I connected it up and you could see the small valve operating inside whereas the old one was not moving.
Not got an oscilloscope to hand and don?t fancy connecting up one from work as its worth allot more than my car so will leave that just incase!
Is the signal always a wave signal or does it reduce down it 0V when either on cold or hot. I?m assuming at some point the valve should get no signal presumably when shut so should I get a 0V reading?
Thanks for your help
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Sat 9 May 2009 10:35
04 1.6 Different heater problem HELP PLEASE - mfarrow
Is the signal always a wave signal or does it reduce down it 0V when
either on cold or hot.


To be honest I don't know, but if you do a forum search then the answer may just be in there, as it's been discussed before. A genuine Ford valve will, though, rule out that component being faulty. Cheap pattern electric parts hardly ever perform the same.
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Sat 9 May 2009 11:04
04 1.6 Different heater problem HELP PLEASE - goooba769
Cheers mfarrow.

Im going to try and buy another control panel as I suspect i shouldnt be reading a voltage when either on cold or hot as the valve should shut but its not unless I disconnect the cable to it.

If anyone else can give me some pointers Id be greatful.

Cheers
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Sat 9 May 2009 13:22
04 1.6 Different heater problem HELP PLEASE - elekie&a/c doctor
Just to clarify the operation of these heater valves,ignition voltage is applied to 1 pin of the connector plug irrespective of the position of the heater control knob.Turning the heater control changes the earth return path circuit of the valve (pulse switching)to maximum to close valve (cold air).No return voltage to the valve gives max heat.Always use a genuine part for correct operation.Also good idea to check the fuses.hth
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Sun 10 May 2009 07:44
04 1.6 Different heater problem HELP PLEASE - goooba769
elekie thanks for the info so far. So if I have no return voltage (high resistance from control knob) then Ill have a fully open valve so I will get heat? If this is right if i disconnect the fuse I should loose the voltage to the valve and it will close so stopping the hot water going to the heater but when I remove the fuse Im still getting heat from the vent have you got any ideas on this? Or do you think it could be the new valve. Most people seem to have a problem where they only get cold air which I could understand as the valve would go faulty and the valve would shut or they blow a fuse so loosing voltage to valve so again it would shut.
Thanks in advance for any pointers.
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Sun 10 May 2009 10:33
04 1.6 Different heater problem HELP PLEASE - elekie&a/c doctor
No voltage to the 2-pin plug,fuse out ,or plug removed gives open valve and full heat.An easy and simple test for these is to connect a test light or small light bulb across the 2 terminals (valve disconnected)and operate the dash control knob.You should see a pulsing light that changes frequency as the control rotates.hth
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Sun 10 May 2009 11:59
04 1.6 Different heater problem HELP PLEASE - goooba769
.*********

Cheers once again
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Sun 10 May 2009 12:01
04 1.6 Different heater problem HELP PLEASE - goooba769
Got that the wrong way round! Cheers elekie Ill try that later at least it will confirm whats faulty.
Cheers
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Mon 11 May 2009 11:45
04 1.6 Different heater problem HELP PLEASE - goooba769
elekie I tried the lightbulb test and there was no pulsing just a contin light from the bulb regardless of position so I will try and find another control panel and see if this works. Cheers again
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