Hello, and welcome to trying to chase this ghost.
I've had this problem over a year now with no sucess whatsoever. And today my secound fan motor died...

Volvo 855 Turbo, 1997, 260.000km

Water keeps entering the cabinfan housing, this especially troublesome in the winter when the water freezes and ice starts killing the fan...

The AC and circulation blinks red at startup, and i have no idea how to read the error message, and OBD2 doesnt read it either.

Ive spent countless hours searching the internett for every possible solution.
Ive checked all the drains i could find, in the cowl, underneath dashboard, and every drain is open, no clogging. If i turn right, or the car is leaning to the left sideways, the water drains out.

Whats infuriating is how arbitrary the water shows up, sometimes it can take a week before its back, ive had the car inside a carwash and flushed it from all angles, not a single drop showed up inside the fan house, yet while parked outside in rain it will fill it up a bit. and how water keeps entering even in winter when its average -25°c is beyound me. (I dont have a garage)

So, ive checked the drains, all seem to work fine, i have a filterhouse and filter for the AC fan, turning off th AC doesnt change anything, and i havent swapped the windscreen.

I am 2 unscrewing out the fan jobs from losing my mind

Anyone have any idea what could be the problem? the car is in great shape engine wise, and doesnt look bad, so its a shame this issue makes me want to sell the car, and ive had it for over 7 years now with near zero issues beside this.

 

I,m guessing that your "Filterhouse" is the one that replaces the "raincap" pictured below (used if the car does not have a cabin filter)

If you have been in there I'm sure you noticed the fan motor is directly below the "raincap" or your "filterhouse" -

So if the fan is getting water in - that's about the only place it could come from (when the cowl area fills with water (due to clogged drains) and overflows into the fan - does the cabin filter ever get wet when this happens?), or the seal between the body and the climate unit.


On a 1997 your blinking CCM lights mean there is a code stored - to read them (on a 1996-1998) you need Volvos scan tool from back then. I have heard of an aftermarket software solution for that problem - but I don't know what is used to interface with the ODB port.

These guys might have the scan tool answer - and a snippet from his webpage is below. https://diaglaptops.com/wp/dice-units/

 

The car came with that "rain cap" (still have it laying around)
I replaced it with a filter housing from another 850 to get a filter fittet.
The water problem started a little while before i swappet it though, and i had some small hope this could help the problem, which it didnt (Yet cleaner air is always better)

The sealing might not be in its best shape, its been a while since i last took of the cowl, im scared of stripping the sockets by repeatedly screwing it in and out too many times.
Yet i have not been able to find any replacement sealing for the housing. (The seal itself sits tightly in the hole, but i cant remember checking it closely for damages either)


I have drowned the cowl with a hoose a while ago, yet again nothing showed up in the fan housing, causing me to give up and screw everything back in place, only for the problem to yet again return after a while

 

Its seems that water lands on the filter, and runs through it, and then down into the fan housing.
il have to think about some kind of solution to this, im not really sure what options to solving this permanently

 

Hello, I registered to help you. I live in Poland. I have three Volvo 850s, including two turbo R.
I had the same problem and no one could help me. When the air conditioning was on, water flooded the fan because it condensed from the evaporator and had no outlet. She fell at the passenger's feet

 

The cause was a screw from the fan housing that got into the plastic housing where the fan is mounted and together with the water from the condenser flowed down to the drain where the water flows through the floor. She blocked the drain, creating a one-way valve

 

I didn't know about it. I did not remove the dashboard. You can't even look there. I took off the rubber hose that drains water from the housing through the floor outside the car. No. 38 on the diagram you received in response. Only a few drops of water fell.

 

I was sure something was blocking the drain. I solved it. I took a thin strong stiff wire. I put it from the side of the floor where I took off the rubber hose and I wanted to take it out after a while but it was blocked. I will use more strength. And slowly I pulled the screw from the fan housing. The head of which perfectly blocked the flow of water. I hope it helps you. Let me know if it worked. Adam.