How do I improve the series 2A demister performance

[bill van snorkle]

My vehicle has the late series 2a flat heater assembly below the instrument panel. even with a 100% blind over the vehicles radiator the effectiveness of this unit is pathetic. Not too fussed about personal comfort as I can always rug up against the cold. It is the windscreen demisters that concern me most as I really do like to see where I'm going. On these colder damp winter mornings my wifes Trooper windows are clear and demisted within a couple of hundred metres of setting off,but even after 5 miles the Landy heater has only cleared a useless area the size of my hand at the base of each screen. Even after wiping the screen with a cloth it will still fog up. The heater radiator isn't blocked and the fan sounds as though its whirring away nicely but even with both heater box doors closed there is only a weak puff of air coming out of the windscreen funnels.

Have any of you in much colder Europe ever made any improvements to address this deficiency? Would a shroud just forward of the heater fan improve my lot ? Under bonnet space is reserved for other stuff so I don't have room for a series 3 type heater.

bill.

[FridgeFreezer]

I fitted a heated windscreen, that way you're not dependent on engine temperature and the thing clears at the flick of a switch. At the moment I think Devon 4x4 are the only place to get them and they're not cheap. I was in discussion with the suppliers but they were worse than useless and then stopped talking altogether when D44 stepped in.

I doubt it'll help much but the first thing is to fit a hotter stat.

I'd look at fitting in the matrix and/or blower from something else, or perhaps an aftermarket diesel-fired heater (either hot air or coolant heater) such as an eberspacher - again, taking the dependency away from engine temperature and antique parts. Diesel-to-coolant heaters are fitted to some modern vehicles as stock and can be pulled out for minimal money & hassle, or bought on ebay.

[David Sparkes]

I don't know what engine you are running, or how the heater matrix is plumbed in, but one difference between vehicles of the Series era and now is that in the Series the heater was optional, and therefore a bypass route was built into the coolant circuit so that flow could be maintained when the thermostat was shut. This bypass flow still exists even when the thermostat opens, and is in parallel with the heater matrix, robbing the matrix of heated coolant.

What I do in these circumstances, although not yet with a Series Land Rover, is to block off the bypass route, remove any flow control tap in the heater matrix circuit, therefore using the heater as the 'always open' bypass circuit.

Heater output is now goverened by the amount of air flowing through the matrix.

This design now mirrors what is in your wifes' Trooper.

Now you have some heat in the matrix any work you do on the air flow will be more effective.

Good Luck.

[bill van snorkle]

Thanks gents. I think heated screens would be unobtainable over here and a bit expensively risky for our country unsealed roads. Petrol or deisel fired heaters probably hard to find in our sunburnt country supposedly in the grip of man made global warming I do like the bypass on the 2 1/4 engine as it allows the vehicle to still be driven in warm climates even without a fan belt or when the water pump fails, due to very efficient thermo syphon action, but I suppose I could block the bypass hose for the winter months.

Bill.

[Jon White]

How about putting some small 12v fans (eg computer cooling fans) in to shift a bit more air? cheap enough and available in various sizes. You could add one in-line to the feeds to each screen.

Jon

[steve_a]

My first series 3 had a terrible blower when I got it. The air flow was the issue and also heat.

The heat was a massively gunged up heater control, and when sorted it had warm but still bad air flow. The fan is kind of washer drum arrangement on those and I think it had about 3 blades left or something. The mini metro was a compatible swap, do we have any rovers over here? I haven't seen any.

Anyway, slight ramble over, is it the air flow or heat that is the issue, I expect it's flow, since even cold air will clear the screen pretty quickly.

There are some hoses, but aren't they visible on the 2a? I found the one behind the instruments was holed when I pulled it out.

See if you still have any blades, if not then it might be time to find a replacement motor from another vehicle or look at some modern blowers from PCs as suggested.