Webasto Thermo Top E for Golf III TDI with Climatronic

Hello everyone,

I finally installed my Webasto Thermo Top E (in a Golf III TDI, AFN engine, manufactured in 1996, with Climatronic). Unfortunately, the blower fan is not working yet. I used the blower relay provided by Webasto and connected terminal 15 to the Climatronic control unit. This successfully activates the Climatronic after the appropriate preheating time of the auxiliary heater. However, according to the wiring diagram for the Golf, the blower fan cannot start because the blower motor only receives voltage via the central ignition relay.
'Has anyone ever done an installation like this before and can remember the best place to connect power to the blower motor? Is the blower motor controlled via ground? Is an additional relay recommended due to the load, or is the K3 relay from the Webasto sufficient?'

Holgi.

Hi,
It's best to use the existing Webasto relay K3 to power the blower motor, as the pre-wired cables have sufficient cross-section and the appropriate fuse protection (20A) in the Webasto auxiliary fuse holder. The positive connection to the blower motor is located behind the central electronics and is connected via a yellow single connector (T1a in the wiring diagram). The blower motor receives a 'regulated negative' voltage from the Climatronic control unit.

To control the Climatronic, another changeover relay is required. The coil contacts are connected in parallel with those of the Webasto K3. Then, you only need to obtain a suitable constant positive connection (terminal 30) to supply power to the Climatronic in the 'standby heating' (STH) mode. For this, I took the fused positive wire from the original auxiliary fuse holder (S101 in the wiring diagram) on the central electrical unit. In its original state, this constant positive connection permanently supplies power to the Climatronic, presumably to save settings. It is protected by a 5A fuse (yellow insert). I have now tapped into this fused wire to supply power to the Climatronic in STH mode. The measured maximum current draw of the Climatronic control unit was just under 1A. Therefore, the 5A fuse is sufficient.

Best, Andy.

Andy,

Thank you very much for your super-fast reply. I will cascade the two relays, which will save me the second fuse holder and the second fuse. Now I just hope I can find T1a. My VW buddy who has the wiring diagrams is having a birthday party today .

It's great how quickly the answers come here!

Merci!

Holgi.

Hi,

I didn't install an additional fuse holder because it's already included as standard with the Climatronic. I simply tapped into the red-and-white (fused) wire to power the Climatronic with the additional switching relay.
But I think you already understand how to implement it.

Have fun, and if the STH is running, I have a few more questions for you.

Best, Andy.

No problem, you already have my email address. Today, my brother-in-law's computer crashed, which got in the way. I'll get back to you by next weekend at the latest.

Holgi.

Hello guys,
I would like to ask another question about this topic.

I have a Climatronic system with an ECON button in my Golf3 TDI 1Z, manufactured in 1996.

Is it possible to connect the auxiliary heater to an input on the Climatronic system so that, when the auxiliary heater is activated, the vent flaps and fan are also turned on?

Reason: I'm considering installing a parking heater.


Best regards,
your hi-fi

What exactly do you want to know? In my case, the blower motor starts, and I had an installation manual for the Webasto that was intended for a Golf IV, and it largely worked.

@ Holgi: What do you mean when you say that the instructions were largely correct?

My question is whether the Climatronic control unit has a free input that, when triggered positively or negatively, would activate the blower motor and the flap control. Would this then also be reflected accordingly in the Climatronic display (e.g., as a pre-heating function)?
Which terminal on which connector can I find this input?

Regards,
high fidelity

I managed to do it.

Therefore, this topic is now closed.



Best regards.
your hi-fi

Then tell us about it!
Thank you!