[Solved] Ford S-Max I Additional Electric Heater Not Functioning: Observations and Queries

I have S-Maks with an additional electric heater (next to the water heater), which is probably the standard in this model. The problem is that the heater does not work. After firing the blast gives heat only after a few minutes when the engine warms up.

I got into the heater today and said the following:

1. The heater (red and black pair) has a gap.
2. The power supply for the heater (violet-black pair) has a total duration of 12.25V. I thought it might be some time, but I put a 300? resistor on the power supply and the voltage did not budge, and the resistor began to heat up.
3. The brown-black pair (temperature sensor?) Has a resistance of 4k?.
4. I could not trace the relay controlling the heater. If it is a relay R6 - Heated windscreen relay , it seems to be OK, and in any case has no short circuit and is not attached.

Do you have an idea what is wrong? And how should this heater work - does it only turn on when you press the quick windscreen heating button, or also in the normal air conditioning mode? In the summer I checked the heating mode of the windshield and then it blown with heat - now it does not work.

The heater is actually controlled by pwm from GEM (based on the charging voltage, motor temperature, operation status of other devices), and the signal from the air conditioning panel, whether manual or automatic, when heating to max, off. air conditioning, the second thin cord. The main power goes from the box under the hood, through the 80A fuse, to the cabin, to the connector that you unbuttoned. Under the black cover of the electric heater there is a tile with, among others transistors enclosing the heating element.
I've got such a heater for fococus mk2, it's just as good as it is for you, no GEM and the air conditioning panel will be different, but the principle of operation is identical. Like something, tomorrow after work I will shout a schematic from the Russian side to the focus, the colors of the wires agree, a diode with a resistor or bulb 1.2w goes to check if pwm goes

vmario wrote:

1. The heater (red and black pair) has a gap.

Since this is a heater, here is the problem.

_siekier wrote:

The heater is actually controlled by pwm from GEM (based on the charging voltage, motor temperature, operation status of other devices), and the signal from the air conditioning panel, whether manual or automatic, when heating to max, off. air conditioning, the second thin cord. The main power goes from the box under the hood, through the 80A fuse, to the cabin, to the connector that you unbuttoned. Under the black cover of the electric heater there is a tile with, among others transistors enclosing the heating element.

So the voltage on the heater is to be served all the time? I thought it was just a simple heating element with a temperature sensor, but from what you write, it appears that my simple measurements do not necessarily indicate that something is wrong.

Since you have a break in the heater, what else you are looking for.

piotrekwoj1 wrote:

Since you have a break in the heater, what else you are looking for.

1. From what he writes _siekier it follows that I measured the heater not directly with the ohmmeter, but the entire controller, so I could have opened, because the semiconductors in the controller did not start at such a low voltage as the ohmmeter gives.
2. Even, and especially especially, if I have a bare heater burnt, the question remains, why the heater is constantly being supplied with voltage even when the ignition switch is off. I will replace the heater, connect it, and she will burn the battery to me, warming up at the stop. And they slept right away, because it will heat without blowing.

Maybe the heater is controlled by mass?

Colleagues, as I wrote, the voltage is fed to the PTC heater module all the time. Only the transistors in the module turn on the heater's voltage based on the logic sum of two control signals. The heater works only after the ignition, and in principle when the engine is running.
The reasons are to be found in these two thin wires - I described this above.
In the event of it, I will put in a diagram and photos, I worked on it myself in focus.

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edit;
In the appendix, the connection diagram of PTC heater in focus mk2, in s-max is the same, only the numbers of cubes and pins are different, because GEM is different - here you should use mondeo mk4 schematics, because it's s-max based on it.
ptc.pdf Download (332.9 kB)
When it comes to checking the pwm signal coming into the heater, as well as the plus after the ignition switch, it is enough for this LED diode with a 1k? resistor (or 12V 1,2W bulb) and a piece of wire
This is what the PTC heater module looks like inside link
And that's how it presents itself in focus link
a lot of it is on these Russian sites ...

Thanks for all the ideas and remarks. I'll be back to the topic in the autumn.

Witam.Koledzy I have such heaters for Ford Focus MK2 diesel and I have a problem because it discharges my battery on the engine turned off. It can not charge the battery charger, so it needs a lot of electricity to charge this heater. I had installations already originally imported, I connected these 2 thick wires with colors of cubes (white to white and black to black) and these 2 thin cables finished 2-pin cube also connected under the ankle free in depth around the climateronic control and by the program and cable elmconfig included in GEMie PTc heaters.At the beginning I made a mistake and turned on the ptc heaters but the one at the top of the first column WEBA STO and read in google that there is still in the 2nd column heater option ptc.Tą in the first column I checked and turned on the second column and thought that maybe that's why I was discharged by the battery but unfortunately it also does not change the same. Now I disconnected these 2 thick wires and the battery does not discharge, I connected the rectifier I will leave for the whole day to recharge the battery. I have no idea what is wrong that does not turn off the heater after extinguishing the car. Thank you in advance oc.Pozdrawiam.

The ptc heater module has no right to take power in the absence of control - that is, without the plus after the ignition and the pwm signal to be switched on from the GEM module. In my previous post I wrote everything about this subject, including a description of the diagnosis. And another thing is that you can not rule out the damage to the ptc heater itself, no one buys new ones, I also bought a used one, but mine still works the best.

It turns out that the purchased heater is damaged but I will go to an electrician friend and maybe he will think of something with it. Thanks for the help. And those 2 thick wires are + and - ?.

Yes, these two thick wires are + power and mass.

I removed the heaters and connected them under the ankles and feel that it is heating but why does not turn it off at night when it stays in the garage overnight. Only a battery is checked by the meter. I was informed by the information that the heater was turned on to%. Or maybe I, somehow I did not turn it on in GEM as it should and that's why it does not turn off, it just warms up to the max, as much as the battery has power. It happens that the temperature sensor in the cabin was damaged. I do not know what else to check. Because it turns out that the heater should be in working order. And "the presence of an ambient temperature sensor or air conditioning system or I4 motor" must also be enabled in GEMI.

Mercy! Everything has already been written about diagnostics.
You did not check what current is flowing (you must use an ammeter for this), you only measured the voltage. Probably only on the power connector, high current (note, currents of 60A). You disconnected the small two-pin control wiring connector (there goes power on the key and the pwm signal to control the heater modules)? If so, and the heater is still heating, it is damaged, dismount it as soon as possible, unless you want to let your car go with smoke. In GEM you do not wind up too much, you just turn on the additional heater and the PTC heater as I remember correctly, nothing more, unless you want to mess it up. In clocks it depends on what you have, like full poverty, before the lift, without a combustion computer you will not see information about the operation of the heater, in other types of indicators depending on the programmed display options (HEC module are clocks).

For me, the topic ended with Wife - the heater turns on after setting the mode Car in air conditioning.