Re: Heater Fan Motor in a 463

I haven't done mine but I have studied the workshop manual. It is involved and has the potential to take some time. Are you sure that the fan is at fault? Symptoms?

That sounds rather bad. The motor is located at the bottom of the heater matrix which is behind the centre consol and at the bottom. The manual talks of removing the centre consol both the one on the dash and the one between the seats, removing the sides to the centre consol and getting to it from below.
The consol between the seats and the side bits are not too bad. Try that and see what you can see. Do you have a/c?

I've got a Workshop (WIS) manual which covers this, but I don't know how to copy sections of it to stick on here. You can buy copies on ebay for a fiver now, 2DVDs, these cover many aspects of the Gs. Otherwise there has been previous posts here about the centre consol removal in detail.

Hi the rubber non return valve at the bottom of the air intake duct for the heater clogs with leaves which allows the duct to fill with water (either rain or washing) and the water floods the front bearing of the fan motor.the only way to lube the bearing without stripping the dash and the adjacent area is to run the front of the G up some fairly steep ramps. lay across the top of the engine and with an extended nozzle on an aerosol can of lubricant feel behind the fan for the shaft... move the nozzle back to where the shaft enters the body of the motor and spray a little lubricant on to the shaft and motor housing.... climb off and run the fan...repeat until the screech disappears..unblock the drain valve and vacuum the bottom of the intake box......if the fan blades do not rotate freely by hand the motor will load the speed resistors and ultimately burn them or the motor......

I used to own a 123 series and the fan squealed. I would mess about lubing itbut it would only last a month and then be squealing again

I am a new member, so apols if this has already been covered. My (463) heater fan screeched a bit then stopped working. Was living without it, but then the main rad blocked, pressured up the system, and the heater matrix blew, producing an instant foggy sauna. Taking the dash out is fiddly but everything screws together well so just take your time. The motor is inboard of the fan so not directly in the plenum chamber, but it has open brush holders which in my case had basically worn down to nothing then overheated (was at around 120,000 miles and 14 years). The bearings are spherical bushes held in by spring strips and these make a screeching noise when the bearing sticks on the shaft and rotates in its holders. I bought a Kenlowe 6-inch fan (actually 7 inches) direct from Kenlowe for £75 inc VAT and PP. This fits as if made for the job, with only a little cutting away at the plastic housing required. It uses the existing resistive speed controller. It is designed to sit out in front of a radiator so should be OK in the damp.
The plenum chamber drain should not get leaves in it, as there is a grille above it, but mine had a collection of twigs etc. The drain is at the front offside corner of the plenum chamber accessible under the bonnet - centre of the bulkhead, and in future I'll poke a stick down there from time to time. The heater matrix was a straight replacement for £99 + VAT, and easy enough to slide in. Just lots and lots and lots of patience and don't panic when you see the birds nest of wiring behind the console! And remember to label the connectors or write down the byzantine MB labelling scheme...

In my 463 (300GES petrol 1991) it is inside the fan housing right next to the fan. It's a small PCB about 5-6 cm square with some resistive wire and 4 x connectors - all different sizes so makes it easier to re-assemble correctly! It mounts on a couple of pillars build into the fan housing. I would say that it is very unlikely to be faulty however: the fan motor brushes are a definite weak point in the setup.

let me know if it looks like the right part?

I was afraid of that. :(