W124 heating / air conditioning air flow

[steve moores 1]

Hi there

Perhaps the forum could provide guidance?

My '95 model W124 coupe (E220) is having difficulty blowing air through the ventilation grilles. :?

If the air con blower is set to cool then this works fine for 3/4 hour or so then eventually the air just trickles out regardless of the fan setting.

At first I thought this was something icing up, however, over this winter period the same happened with the heater. After 3/4 - 1 hour or so the hot air only trickles out of the vents leaving the passenger compartment quite cold. :x

I assume this sympton takes attention away from the air conditioner and points it towards the heater / fan assembly; but in reality I'm a bit lost. :?:

Can anybody advise?

Regards


Steve

'95 E220 Coupe auto

 

[NormanB]

Hi Steve

Me know nothing about your nothing about your particular model........But proceeding from first principles and assuming your blower is spinning I would hazard a guess there is a flap shut somewhere - I believe these are vacuum operated on some models.

Also it may be worth checking your pollen filter (if fitted) these can get forgotton about and do get leaping enough to cut down air flow.

Let us know how you get on.

NormanB

 

[Keith]

air not blowing

I do have a fair bit of experience eradicating this sort of problem on my own E class.

When it dies can you still hear the blower going or does the blower appear to stop/go quiet?

If it seems to stop then I would put a bet on it being a fuse box problem. The issue is that the heater blower fuse (look it up on the lid of the fuse box) gets so hot that it distorts the plastic in the base of the fuse box. The fuse then moves downwards and contact is broken with the brass clip on the top of the fuse. You can test if this is the issue by stuffing a small ball of cooking foil under the bottom end of the fuse to raise is by a couple of mm. Try that for a few days if that cures it then thats the problem but dont leave it there cause the foil will melt also. The proper solution is to add an additional special fuse box just for the blower. Being lazy I took another option which was to utilise an unused fuse position, move the blower fuse to a new slot and wait another 6 years before the plastic distorts in the new position enough for the problem to reappear.

I hope it is the cause , it took me many hours of shadow boxing to arrive at that one and its so simple to sort out.

If the kitching foil doesnt cure it then let me know, especially can you hear the blower after the air stops.

Hope this helps
Keith

 

[steve moores 1]

Thanks chaps.

However, there is apparently no pollen filter on this car and the blower still spins forcing air out, however, at a much reduced volume flow rate and is much quieter. Does this help?

Regards


Steve

 

[Keith]

blower/air

Steve
I would still check out the fuse , there's nothing to lose. When mine first went on me the blower sort of petered out and then sometimes would work again until it stopped.

It does sound like either the power to the blower , fuse , switch or or the blower itself . Unfortunately before realising the fuse issue on mine I went and got the blower motor replaced and the pollen filters (the motor was £178 plus VAT and fitting was £75 plus VAT :x )

I would check out the electrics before deciding the blower motor has gone.

Keith

 

[NormanB]

Steve

Have a read of this - it may help in your diagnosis:

http://www.mercedesshop.com/shopfor...37266&highlight=blower+motor+and+resistor

NormanB