The PTC heater element has a permanent 12 Volt power source. This is the big (10 mm2) cable which is connected to the Battery junction Box. The 2 small wires which are connected to the PTC heater element come from the GEM module/fuse box. These wires carry a PWM (Pulse Width Modulation) signal which controls the capacity of the heater element. This way the heater elemant can be regulated fom 5% to 100%.

The heater control panel is connected to the GEM module/fuse box. In most cases this wiring is already present. If the wiring is present you only have to activate the PTC heater function in the software of the GEM module/fuse box after the PTC heater has been installed.

Thank you, mate! Your help is priceless for me.

My main problem is that below. I don't have the wiring. In this occasion, do you know how can I make the connection?

The heater control panel is connected to the GEM module/fuse box. In most cases this wiring is already present. If the wiring is present you only have to activate the PTC heater function in the software of the GEM module/fuse box after the PTC heater has been installed.

The easiest way is to take the wiring out of a scrap car. Usually the higher spec diesel versions do have the wiring factory fitted but my experience is that some petrol versions do also have the wiring factory fitted.

On my MK2 First Edition (a trim level just below Titanium) with a 1.6 Duratec 100 HP engine the wiring from the GEM module/fuse box to the PTC heater element was factory fitted. The big (10 mm2) cable which is connected to the Battery junction Box was not factory fitted on my car. I made this wiring myself using some 10 mm2 cable and suitable cable lugs.

I've already made the wiring from the fuse box to the PTC heater myself too . My question is regarding for the other two cables left ( from total of four) ? Sorry if I havent't been clear enough and any inconvinience caused. Many thanks.

Do I have either of these heaters fitted? 2008 1.6TDCi Titanium. Seems to take forever to warm up though. My old 306 HDi had a coolant heater and that gave heat within a mile, the Focus is still cold after 4 miles!

I've already made the wiring from the fuse box to the PTC heater myself too . My question is regarding for the other two cables left ( from total of four) ? Sorry if I havent't been clear enough and any inconvinience caused. Many thanks.

The wiring can be well hidden behind the dashboard. If the wiring is not present you have to install it. The wiring schematics of the Focus MK2/MK2.5 can be downloaded from this forum.

Do I have either of these heaters fitted? 2008 1.6TDCi Titanium. Seems to take forever to warm up though. My old 306 HDi had a coolant heater and that gave heat within a mile, the Focus is still cold after 4 miles!

The Fuel Fired Heater or PTC heater were optional in most Western European countries. In some countries the PTC heater was not even on the options list. It is a known problem of most diesel engines that they warm up very slow. Installing the PTC heater system will be a big improvement.

JW, I think I wasn't clear enough and you have misunderstood me. I'll try to explain it again with pictures.

Below is the pic of the PTC heater and the 4 cables that come from it. I've already wired myself the wiring for the big cable. My question is for the other two cables ( thin ones, black and brown, the ones on the right side below). My car doesn't have the socket to connect/plug them. Do you know how I have to make the connection in that occasion? I hope you understand me now. Thank you in advance for your cooperation. I am looking forward to hear from you. Cheers.

The wiring colors of the PTC heater element are different from the wiring colors of the cars wiring loom. The 2-pole connector on the PTC heater element has the pin numbers casted into the connector.

Pin 1 of the PTC heater element connector is for the IGN. This should be a Green/Orange wire and further (after a connection) a Green/Black wire. This wire goes to Pin 5 of the C102 connector. The C102 connector is the big blue connector of the GEM module/fuse box.

Pin 2 of the PTC heater element connector is for the PWM signal. This should be a White/Black wire. This wire goes to Pin 9 of the C103 connector. the C103 connector is the small blue connector of the GEM module/fuse box.

Hello everyone!

Sorry for bringing up this old thread, but I believe it is better to ask a PTC heater related question here, than to open a new thread.

I have a question regarding the part numbers of the heater control panel that support PTC heater, which have been posted on the previous page:

Red ellumination:
7M5T-19980-BA
7M5T-19980-BB
7M5T-19980-BC

Do really only these three part numbers support the PTC heater, or is it the case like with PJB (the "higher" the letter the higher the part specification)?

I am asking this because I have an AA control panel number, and I am having difficulty finding these exact three part numbers.

I have found control panels whose part numbers end with BD, or BF. Do these part numbers support the PTC as well?

Thanks

Part number 7M5T-19980-BD will also be suitable.

This is the latest part number which supersedes the part numbers (7M5T-19980-BA, BB, BC) I mentioned in my previous post. All other part numbers are not suitable.

Manual heater control panels wich support the PTC heater function are pretty rare. In some European countris this option was not even available. Best chances to find one are in Eastern Europe, the baltic states or Russia.

Part number 7M5T-19980-BC will also be suitable.

This is the latest part number which supersedes the part numbers I mentioned in my previous post. All other part numbers are not suitable.

Sorry, maybe it's due to the light headache, but I don't understand. That part number was mentioned in your previous page post!

Did you mean to say 7M5T-19980-BD?

Thanks

I did indeen mean part number 7M5T-19980-BD.

I did indeen mean part number 7M5T-19980-BD.

Great, thanks!

Hi guys.

I want to install PTC but I do not have the big wires from battery junction box  to the PTC.

Can help me someone's with a photo from the ground big wire în the car?Where is connected on the floor?Thanks.

 

On 11/5/2014 at 7:06 PM, JW1982 said:

There are a few different versions of the Focus MK2/MK2.5 heater control panel for manual A/C. On the outside all heater control panels look identical but inside there are technical differences. The versions which are suitable for the Fuel Fired Heater or PTC heater have a different circuit board with some additional components.

The heater control panel can be identified by the part number. This part number is located on a sticker at the top of the heater control panel. The following part numbers are suitable for the Fuel Fired Heater or PTC heater:

Green illumination:

3M5T-19980-BB

3M5T-19980-BC

3M5T-19980-BD

Red ellumination:

7M5T-19980-BA

7M5T-19980-BB

7M5T-19980-BC

The prices of a new heater control panel which is suitable for the Fuel Fired Heater or PTC heater vary between €225,- and €300,-. The version with green illumination is a bit cheaper than the version with red illumination. These heater control panels are a bit rare in Western European countries. These heater control panels are Occasionally offered on ebay. Mostly by eastern European sellers.

Hi and thanks for all info.
I dont have the heater control panel you listed as suitable.I have the one with a difference apperance like in picture.

Do you know the part numbers for me to use?

 

Thanks, Morgan

On 11/5/2014 at 7:06 PM, JW1982 said:

There are a few different versions of the Focus MK2/MK2.5 heater control panel for manual A/C. On the outside all heater control panels look identical but inside there are technical differences. The versions which are suitable for the Fuel Fired Heater or PTC heater have a different circuit board with some additional components.

The heater control panel can be identified by the part number. This part number is located on a sticker at the top of the heater control panel. The following part numbers are suitable for the Fuel Fired Heater or PTC heater:

Green illumination:

3M5T-19980-BB

3M5T-19980-BC

3M5T-19980-BD

Red ellumination:

7M5T-19980-BA

7M5T-19980-BB

7M5T-19980-BC

The prices of a new heater control panel which is suitable for the Fuel Fired Heater or PTC heater vary between €225,- and €300,-. The version with green illumination is a bit cheaper than the version with red illumination. These heater control panels are a bit rare in Western European countries. These heater control panels are Occasionally offered on eBay. Mostly by eastern European sellers.

Hi and thanks for all info.
I dont have the heater control panel you listed as suitable.I have the one with a difference apperance like in picture.

Do you know the part numbers for me to use?

Thanks, Morgan

Here are numbers for automatic climate control with inbuilt switch

Originalnumber: 1698893

On panel number: 7M5T18C612CE

Hi,

by coincidence i stumbled over htc heater on the web so i i had to check if i got one and i did. Its factory installed from new.

It wasnt working so i ordered one from junkyard and fitted t, it works.PTC is enabled in GEM

But some funny stuff is present

Its not visible on the instrument cluster
If i enable in IC "HTC heater chimes"(something like that) it is visible in instrument but only says Heater -- and the fuel consumption --

Its on all the time from 16c to max temp, outside is 0c, engine temp is about the same.
I can confirm its on all the time with ohm-meter on little brown cable from heater element, its shows ~1.5v.

I have ordered a new used control unit, hope it works at it should then.

Its on but ECU does not think so...

anyone got any idea for this problem?

thanks

Edited February 25, 20242 yr by fofo
Added info

Hello guys,

I see this topic has been inactive but I'll try my luck anyways.

I have fitted the PTC Heater, the cables from the engine junction box, the cables going to the GEM C103 and C102 connectors, as well as an extra cable from the Climate Control Unit to the GEM C103 connector on pin14 (i saw a russian guy on yt that said to do that so the CCU can send a 12V signal to the GEM so it can start the heater)

Afterwards I connected ElmConfig and activated the GEM option for the PTC heater on page 3 (the first one because I don't have automatic climate control) and the option in HEC showing PTC status, however the HEC always displays "Aux. Heater off".

Do you have any ideas or advice how I can fix this?

 

*The CCU ends with a BD and gives a 12V signal

**The Fuse Box ends with BD as well

On a Focus MK2/MK2.5 with manual heater control (rotary knobs) the temperature knob must be turned to maximum to activate the PTC heater system. This requires a heater control panel with an integrated microswitch. 

The PTC heater system can only be activated if the outside temperature is below 10 degrees Celsius, the engine is running, the battery is sufficiently charged and the alternator is able to charge the battery. The PTC heater is the first system to be switched of when the power consumption is higher than the alternator can charge. Therefore the alternator should be at least 120A but preferably 150A.


If the correct heater control panel and PTC heater element are fitted and the system is wired and configured correctly the system should work. 

When the system only shows "Aux. Heater Off" there can be 2 possible causes:

1: The conditions for the system to be activated are not met. 
2: the GEM module is not capable to control the PTC heater.

AS far as I know the Focus MK2.5 did literally have dozens of different GEM modules. Many of the lower spec versions do not have all hardware components fitted and therefore lack functionality.

I was hoping you'd reply as it seems you are the expert on the topic JW.

The conditions are met (engine temp. below 60⁰C and outside temp 2⁰C)

Wiring is correct, checked and double checked.

Climate Control Unit sends 12V signal - checked.

The only thing left is the GEM module and I cannot find a list to see if my GEM module supports this. (7M5T-14A073-BD)

I have done some digging around and found out that my GEM module lacks the necessary specs in order to activate the PTC Heater Function.