Ford Ka heater just blowing hot help

[goooba769]

Iv got a 2004 ka sport and the heater just gives hot air all the time regardless of what position its in.
Can anyone give me some advice on a fix please?
Im assuming the heater control is a variable resistor of some kind and the voltage varries when the knob is turned? If I measure the voltage will this work?
Assuming this confims the control is ok what next? Iv noticed some comments about a valve but not sure where this is and how it works if someone can give me a pointer please?

 

[Burnerman]

The Ka, like the Fiesta and many others, has a control valve that is electrically operated and known to fail. Its usually located in the top pipe leading to the heater radiator, close to the bulkhead.

 

[goooba769]

right then Iv found the valve and there is a constant voltage going to th valve regardless of where the heater control is positioned. I have removed the ontrol panel and measured the rsistance on the variable resistor and its low and makes no difference when i turn the control. Am I rght in thinking the resistor is buggered and just keeps the valve open so heater on all the time?

 

[tommydickfinger]

just replace it gooba- no1 tests them-ever- they always fuk up

 

[woodywobblestick]

Just finished fixing my heater tap. Was stuck on about 2 thru summer and winter now fast approaching. The 'tap' is located behind plastic bulkhead just under windscreen center. The 'tap' is not cable operated like most old cars but electronic. It uses a variable solenoid to pull the hot water valve open or shut. Failure in my Ka was beause the solenoid and piston got dirt inside which stopped the sliding action. To get at it;
Remove wipers and plastic panels beneath them. In the middle of the plastic bulkhead there is a cover perched over the heater 'tap'. Difficult to get at without small mirror and lots of light. The cover is meant to keep rain off the tap solenoid. I cut mine off with a soldering iron cutter and rewelded it back when I finished. Plenty of access during operation. Remove clip holding electrical connector , remove connector. At this point it is worth testing the electrics with a multimeter (12v-20v). Put test probes into each socket of the connector. Get someone to put ignition on only and turn heater dial from cold to hot. You should see voltage rise and fall from 0-12v. If not check your fuses or switch.
Remove the Solenoid (alloy bit) by undoing 4 small star head screws. (A flexible drive is handy here) You can leave the piston (shiny chrome rod) in the valve seat. If you really want to test the tap then assemble the piston in the solenoid and test like you did for voltage (with the electrics connected of course) after cleaning. The valve will pop in and out if it works.
Clean the inside of the solenoid back to a bright brassy shine ( I used pure achohol and tissue). Clean the chrome piston. Putting it back requires lining up 2 back plastic lugs of the connector base into 2 holes on the valve. The valve face is the chrome plate bit. Put your 4 screws back, connect the cable and test for leaks and operation by starting the Ka and getting the temp up. The rest is history.

 

[nihonsuki]

<snip>
Remove clip holding electrical connector , remove connector. At this point it is worth testing the electrics with a multimeter (12v-20v). Put test probes into each socket of the connector. Get someone to put ignition on only and turn heater dial from cold to hot. You should see voltage rise and fall from 0-12v. If not check your fuses or switch.
<snip>

I've just checked my coolant valve for the same reason. I've checked the voltages at the terminal entering the solenoid, and it seems to be varying between 7 and 15V, that is, turned to hot (I think) it stays around 15V, turned to cold (or opposite) it sits around 7V and in between it switches every few seconds. Halfway, the period of switching is slower. The solenoid resistance is ~1ohm. Looks like the solenoid is shot, but what do those voltages suggest for the control panel?

TIA

 

[woodywobblestick]

Voltages ok then suggest you get a brand new solenoid heater switch from ebay. I got mine for about $25 and now works a treat. Installation is tricky because of the confined space but you must be very careful not to pull hard or push laterally on the hoses where they enter the heater core pipes. IF they are plastic they could be easily broken and you would have to remove the dash to fix that. Use a clamping/multigrip plier to squeeze and loosen hose clips. The pipes on the old solenoid valve are plastic and will break (not that it matters) but make sure that pieces are accounted for and not left in hoses. The solenoid unit clips onto edge of firewall. Take a photo before you start to recall the layout on reassembly.

 

[woodywobblestick]

7-15v divergence is still a 12v difference , your voltmeter is out by 7v. As you have a 12v battery I suggest the Ka's real voltage is only 12v.

My cleaning of the piston originally, resulted in a small water leak which caused clogging of the piston again, hence the new unit was purchased an installed.
Need to remember that the Ka's are getting to be 10 years old and plastic components and heat cause them fail. I also had to replace my CoilPak (dizzy leads and coil leads) when I had persistant misfiring. Cost me $300 but next time I'll buy a coilpak on ebay.
The Ka's economy more than makes up for the crap I occasionally put up with.
the other item to watch is the thermal resistor at the bottom of the radiator. The later models have an encased coil - they can burn out and the fan will not work unless aircon is on. Simple replacement but pricey. Check wrecking yards.

 

[nihonsuki]

Voltages ok then suggest you get a brand new solenoid heater switch from ebay. I got mine for about $25 and now works a treat. Installation is tricky because of the confined space but you must be very careful not to pull hard or push laterally on the hoses where they enter the heater core pipes. IF they are plastic they could be easily broken and you would have to remove the dash to fix that. Use a clamping/multigrip plier to squeeze and loosen hose clips. The pipes on the old solenoid valve are plastic and will break (not that it matters) but make sure that pieces are accounted for and not left in hoses. The solenoid unit clips onto edge of firewall. Take a photo before you start to recall the layout on reassembly.

Cheers! I've ordered a heater control valve for £13 of ebay - cheaper than yours at current exchange rates! Access seems fine with the bulkhead plastic out of the way. This is a 2006 car, so hopefully the pipes haven't become too stuck to the valve. Meter was reading low battery on closer examination, so maybe that explains the 7V drift. Thanks for the precaution list, I'll give them full regard when I'm switching valves.

 

[kitkatjeff]

Just been reading on here all the problems with ka heaters. l have the same problem with my daughters 2007 ford ka only blows hot air out, no cold at all. l replaced the unit inder the bonnet but still no better. After reading the posts on here l have just connected a meter across the wires and am getting a constant 12volt reading where ever the heating switch is. l assume then that it is the actual switch in the car that is faulty but can antone confirm this? Thanks.

 

[Burnerman]

Thats certainly what I'd go for - the switches do fail, but at a far less frequency than the heater valves.
John

 

[kitkatjeff]

l replaced the unit under the bonnet as it had started to leak and had been blowing for a while. Put it all back together again and still the same. Thats when l read in the forum about testing the voltage at the lead. Put meter across the leads and it is just a constant 12.8 volts, doesn't make any difference where the switch is turned to, no variation. Taken the heater panel out inside the car and had a look to make sure the pin was actually turning which it is so can only assume that it is this what ever it is called that has failed,