Climatronic Wiring Harness: Troubleshooting Guide

I want to buy a Climatronic wiring harness on eBay. However, this harness is for the Climatronic system from a 1992 Passat 35i. I want to install it in my Passat 35i, which is from 1996. Does anyone know if there are any differences in the pin configuration?

Best regards, WarLord.

Hello WarLord.
Having researched this topic in recent days, I can tell you the following: Generally, the wiring harnesses are usable. However, there are differences in the radiator fan control, specifically whether it's a 2- or 3-stage system, depending on the engine code and whether the vehicle has a trailer hitch or an automatic transmission. In any case, you should obtain a wiring diagram for the specific vehicle due to the different pin and connector configurations in the central electrical system. However, this is not a problem with some basic knowledge of electrical systems.
You can obtain wiring diagrams for 93 models from me, provided you specify the model year and engine code.

Best regards, Benno.

Hmm, that sounds like a cobbled-together solution. My Passat is a 35i, manufactured in 1996, with a 1Z 90 HP TDI engine, no automatic transmission, and an aftermarket tow hitch. What's the difference between the two-stage and the three-stage versions?

Best regards, WarLord.

Hi, can I join in?
I installed a manual climate control system in my PD last year, and it's something you shouldn't underestimate!
Okay, here's the translation:

'I'm going to install a Climatronic system in my G3 1Z. I just bought the parts on eBay and I'm eagerly waiting for them to arrive (including the complete wiring harness!). Now, I have a specific question. Do you think it's possible to install the manual climate control system from a 35i into a G3? I've already compared the parts on edgar, and of course, the A/C hoses won't fit perfectly. But what about the blower motor housing, the electrical components, etc.? Can anyone send me a wiring diagram for the climate control system of a 35i? I have quite a few from G3 and G4 models that I can use for parts. I also happened to already have a climate control wiring harness from the engine bay of a 35i.'
Best, Tom.

'I was also wondering about whether the Golf III parts would work, as I was even considering a Golf IV Climatronic (which are cheaper on eBay). However, I gave up on that idea (because I don't really like the blue color, and I also find the 35i parts to be very well designed), as I found an ECU on eBay (with an ECO function for the 35i). I just need a precise diagram showing which wire goes where and what the pin assignments are (for the 35i). I already have the SSP manual, but it doesn't cover the pin assignments for the components on the housing. I already have a manual climate control system, but I'm going to remove the entire heater box, install the new one, replace the dryer, and thoroughly clean the entire thing with compressed air and nitrogen (of course, before the dryer), and then refill it. What year is the climate control wiring harness from for the 35i? I already have one heater box (from a 35i 89-93), but I'm going to get another one because some parts are broken on mine (including on a vacuum sensor), and the seller insists that the unit worked perfectly for him.'
Best regards, WarLord.

Hello!

The differences between the wiring harnesses aren't that significant. For example, the 3-speed fan has an additional control unit for the radiator fan. Depending on the year of manufacture, it may also be present in the 2-speed fan system, but in that case, the 3rd speed is simply not activated. In the Turbo Diesel (AAZ) and VR6 engines, the air conditioning is also switched off if the coolant temperature is too high. If you install one of these wiring harnesses in a 1Z engine, you can leave the connectors open. However, you should know what each connector is for, otherwise you'll be plagued by doubts. To my knowledge, the Passat 35i facelift also has a control unit for the 2-speed fan, located in the front of the engine compartment.
However, it doesn't necessarily have to be installed if you're using the existing wiring harness. It's also important to know that the pin configuration in the central electrical system changed starting with the model year 94 (although the function remains the same). Therefore, I strongly advise checking...
Please refer to the wiring diagram of the donor vehicle.

Since you're likely sourcing a used Climatronic system, be sure to consider the "small details" as well. In addition to the main components, you'll need: the temperature sensor for the heater radiator outlet (located in the hose in front of the radiator), the interior temperature sensor with blower (located in the dashboard between the radio and speedometer), the corresponding large dashboard trim piece, as you can't easily create the cutout yourself, the air distribution duct for the vents above the radio (which includes a flap with a vacuum actuator), the photosensor in the left speaker cover, and finally, the relay for climate control socket 1. If even a single part is missing, the extra cost can be significant.
Before installing the housing, you should definitely test the servomotors for the flap control. Refer to the wiring diagram to find the two wires for each motor and apply 12V. You should hear the motor running. If not, reverse the polarity, as it may be at its limit. If it still doesn't run, it is defective and must be replaced.
Here's another tip from me: if the blower motor isn't working, the climate control relay contains two individually controllable relays. One of these relays supplies the entire power for the blower motor in the Climatronic system and is heavily loaded. As a result, the solder joints can become loose over time, leading to failures such as unexplained intermittent contacts. Instead of replacing the expensive relay, resolder the large connections inside the relay. This also applies to relay socket 3, which provides power to the engine control unit.
And now, have fun installing it!

Okay, since I already have a manual climate control system, I probably won't need the part you're talking about, right? Do you have a picture of where that part is located?

Best regards, WarLord.

Hello Warlord,
The parts I mentioned are only available with Climatronic and not with the manual air conditioning system, except for the relay.
That's why I specifically wrote the list.
Above all, it's about the cutout. It's not just a hole. A temperature sensor is clipped in from the back, and a small cover grille is attached from the front. I'll try to see if I can copy a diagram from AKTE.

Best regards, Benno.

Ugh, this is such a pain. I'm already annoyed by the whole thing. I think I already have the necessary cutout (at least in the cover). Can you also send me some pictures of the air ducts (including the differences from the manual climate control)? Are the boxes different between the B3 and B4 models?

Best regards, WarLord.