so the fan drops off , okay that explains something on mine , lots of air movement in the compartment, but bugger all output
I,m sure you would have checked, but make sure the air hose hasnt jumped its (large) jubilee clips at either end, very easy to come loose if it hasnt been put on corectly and tightened due to lack of space.
Found that this was a 2 man job to keep clips in place when tightening to be 100% of then locating deep enough. The ridge from the heater box / fan and also into the passenger compartment could do with being at least a full centimeter rather than just about the height of the clip itself.
checked output from top of fez box, its minimal.
need to workout easiest way to clamp off water circuit for removal.
There is need to clamp off water circuit of the hoses, jack car up at front so any flow is to the rear. Keep the two hoses pointing upwards and tiewrap out of the way whilst you work on removing.
The only coolant lost is what is in the heater matrix on take off, about half a cup full, and nothing when ypou refix as the coolant has moved towards the rear of the lines, just top up avery little when the job is done.
(Sounds like I,m an expert, but just a good apprentice and watched very stage of the work being carried out. Apart from the dremel it seemed the best tool was a pair of long pincers, in order to hold the allen keys that held the fan to the heater matrix, and remember to use magnetic ones.) (It will be a sod when everything is virtually in place and you drop a screw or allen bolt into the chasm!)
Also test the fan is working as required before putting anything back in situ.
The final work is to tiewrap the loom back into place and replace the cover on the right (as looking at the car), it has to come off to get the hrater in, it really is a tight squeeze.