Ford Ka - Heater Control Valve

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Wed 1 Aug 2012 19:08
Ford Ka - Heater Control Valve - BenjiBMW

Hi,

For a few months I've had a problem with my heating in my 1997 Ford Ka. Whatever I set the temperature dial to, it has no effect on the air tempurature. As far as I can tell it's just feeding through cold air without any heating whatsoever.

I'm aware that the HCV can be a problem on these, so I took apart the grilly thing below the wipers to inspect it. When I got there I tested both the connections going into the unit. One is purple and black and the other is green and black. On the purple wire I am getting a constant 12V connection, which I assume is the power supply to the valve in the HCV. However, on the green wire I was getting no voltage whatsoever no matter what I put on the temperature dial. As far as I know this SHOULD be sending pulses to control the position on the valve.

As there is a problem with the input, should I assume it's most likely the actual controlling dial that's died or should I continue to inspect and possibly replace the HCV itself.

In terms of replacing the controlling dial is there any way to control just this part of the control panel or would I need to replace the entire panel?

Cheers very much,

Ben Marshall

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Wed 1 Aug 2012 19:50
Ford Ka - Heater Control Valve - elekie&a/c doctor

You need to put a test light or meter across the two wires.One wire is ignition supply and the other is a switched pulsed earth return from the heater control panel.hth

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Wed 1 Aug 2012 21:06
Ford Ka - Heater Control Valve - BenjiBMW

You need to put a test light or meter across the two wires.One wire is ignition supply and the other is a switched pulsed earth return from the heater control panel.hth

Ah I see I thought it was just some sort of positive pulse so was holding it to an earth! Now that I've done it correctly, I can see that the signals are indeed being generated as they should be. I.e. 12V with a drop down pulse every few seconds at 50% on the thermostat control.

In this case shall I assume that it is the heater control valve itself that needs replacing? Seeing as though there are a million posts on the internet suggesting that this is a common fault on both Ka's and Fords in general around this time period! xD

Cheers,

Ben

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