There is literally nothing we can do from a distance to assist with this.

We can't smell what you're smelling, we can't tell you what it is, we can't tell you where it's coming from, we can't say whether it is related to the air conditioner or not, whether it's potentially dangerous to your health or not.

Have I had a similar experience? Yes, multiple times, but that doesn't mean the causes (which were different in my case) are the same as in yours.

I've had mould or mildew in the evaporator housing of the air conditioner, and yes, that can be hazardous to your health, there are cleaners that can be used, but I just sprayed half a can of lysol into the recirculation intake with the a/c running and that took care of it.

I've had chemicals spilt in the vehicle - oils, battery acid, solvents - you have to find the spill & clean it as best you can, the stink of gear oil is especially hard to get rid of, are they hazardous to your health, some of them probably are, certainly breathing in sulfuric acid fumes is not something I would recommend, and if you have a hole in the air conditioning system allowing exhaust fumes into the cabin, that too would be bad.

What is this "hose going to the air conditioning filter", what does it connect to? What air conditioning filter are you referring to? Is it possibly a coolant hose to the heater core, which is going to be buried in the HVAC (Heater/Ventilation/AirConditioning) assembly behind the dash?

There are, so to speak, two filters in the air conditioning system, the cabin filter, which basically sits in the ductwork behind the glove box (not all cars have a cabin filter) and filters the air that is being circulated, the other which is sometimes called by different names, receiver/dryer or filter/dryer, removes contaminants from the refrigerant in the air conditioner system. The filter/dryer is usually under the hood, somewhere near the air conditioner condenser.

Back to that heater core - coolant tends to have a "sweetish" smell, and if you have a leaking heater core it's possible that it might first be smelt only when the a/c is on and air flowing through the HVAC assembly, but after awhile the coolant will tend to leak into the cabin and usually soak into the carpet so it goes unnoticed, at that point you might be able to smell it with the air conditioner off - BUT - this would be accompanied by a need to be constantly topping up the cooling system which you have not mentioned. Changing out the heater core is timing consuming, so, yes, that would be an expensive repair, if that is what it is, we don't know, and yes, I've had a leaking heater core too.

How about you take a picture of this small hole at the hose so we can at least see what you're describing...

 

Post a small sample of the smell..

 

There is literally nothing we can do from a distance to assist with this.

We can't smell what you're smelling, we can't tell you what it is, we can't tell you where it's coming from, we can't say whether it is related to the air conditioner or not, whether it's potentially dangerous to your health or not.

Have I had a similar experience? Yes, multiple times, but that doesn't mean the causes (which were different in my case) are the same as in yours.

I've had mould or mildew in the evaporator housing of the air conditioner, and yes, that can be hazardous to your health, there are cleaners that can be used, but I just sprayed half a can of lysol into the recirculation intake with the a/c running and that took care of it.

I've had chemicals spilt in the vehicle - oils, battery acid, solvents - you have to find the spill & clean it as best you can, the stink of gear oil is especially hard to get rid of, are they hazardous to your health, some of them probably are, certainly breathing in sulfuric acid fumes is not something I would recommend, and if you have a hole in the air conditioning system allowing exhaust fumes into the cabin, that too would be bad.

What is this "hose going to the air conditioning filter", what does it connect to? What air conditioning filter are you referring to? Is it possibly a coolant hose to the heater core, which is going to be buried in the HVAC (Heater/Ventilation/AirConditioning) assembly behind the dash?

There are, so to speak, two filters in the air conditioning system, the cabin filter, which basically sits in the ductwork behind the glove box (not all cars have a cabin filter) and filters the air that is being circulated, the other which is sometimes called by different names, receiver/dryer or filter/dryer, removes contaminants from the refrigerant in the air conditioner system. The filter/dryer is usually under the hood, somewhere near the air conditioner condenser.

Back to that heater core - coolant tends to have a "sweetish" smell, and if you have a leaking heater core it's possible that it might first be smelt only when the a/c is on and air flowing through the HVAC assembly, but after awhile the coolant will tend to leak into the cabin and usually soak into the carpet so it goes unnoticed, at that point you might be able to smell it with the air conditioner off - BUT - this would be accompanied by a need to be constantly topping up the cooling system which you have not mentioned. Changing out the heater core is timing consuming, so, yes, that would be an expensive repair, if that is what it is, we don't know, and yes, I've had a leaking heater core too.

How about you take a picture of this small hole at the hose so we can at least see what you're describing...

"There is literally nothing we can do from a distance to assist with this."
I completely understand - but therefor you helped me a lot with your ideas! Many thanks for that! It's just what I'm looking for - some ideas or experieces I can go on with...
Sorry - I can not post a picture. The technicians from Suzuki have been looking for the car when I was absent. I am not good in DIY and not able to open everything to reach the filter or others. Again: thank you very much!

 

I'd disconnect the AC lines and reconnect after a few minutes. Aside from gas or oil, thats the only other chem smell you're gonna get.

 

That would be illegal to exhaust the refrigerant into the atmosphere

 

A leak into your cabin will also kill someone.

 

The correct measure is to have a qualified station draw down the system..

 

'IF' the smell is from the left over rat problem some cloth bags of fabric softener and/or a pan of baking soda in the floor board (careful not too much where it could spill out) left for a while may take care of the problem. I've had to do this before. I have also sprinkled baking soda on the carpet and then vacuum it up the next day. Good luck!