Series 3 Heater Blower/Fan

Series 3 heater motors have a poor reputation for not being very effective but this is not really true when everything is in good condition. The main problem is there are a number  of components that, when they fail, can lead to less effective air movement. Firstly the snail cases tend to rot and therefore leak air, the hose from the heater to the matrix needs to be in good condition with no splits as this will also impact the amount of air getting to the cab. There is also a seal between the heater matrix and the bulkhead that should be air tight and also a seal on the other side between the bulkhead and the dashboard/air box. Then you need the lower dash to be in good condition, unfortunately the vinyl cover usually hides a lot of rot and holes where air can escape. The vent direction flaps are also poorly designed and tend to seize over time so you either get little air through the windscreen vents or little through the lower vents. If all these things are in good condition then the Series heater is absolutely fine and very effective.

Amongst some of the stuff I had galvanised recently were a batch of series 3 heater motor ‘snail’ cases. I had them all shot blasted first and then welded any areas in need of repair. Not easy to weld as the steel is very thin and non existent in places! They turned out well, just had to drill out the galv from the bolt holes and I’ve retapped them to metric and will be using stainless bolts and washers. Of course being galvanised they won’t rust!

Series 3 heater fan snail case

The cases have had a couple of coats of etch primer on the outer case and then a few coats of black gloss as per the the originals. I’ve left the inside of the case bare galv.

I’ve also got a stack of Smiths heater motors that I’ve stripped down. The motors are very simple to strip down, they are usually pretty rusty so sometimes need a little persuasion to come apart. Just unplug the pos/neg wires from the motor and undo the two little nuts at the back of the case. The back of the motor case can then be removed and you’ll see the brushes. You’ll need a container to keep all the little bits together. I clean up the brushes using brake cleaner as it does not leave an oily residue, WD40 or switch cleaner should not be used on motor brushes for that reason.

Series 3 Heater motor brushes

Before trying to remove the shaft I’d recommend cleaning the external section of the motor shaft with some fine emery, there is a brass bearing/bush just inside the case and this will come out of it’s housing when you remove the shaft as it will be stuck on the shaft if you don’t clean the shaft first. It’s not the end of the world if the brass bearing comes out but it’s a bit fiddly getting it back in again. One the shaft is out the commutator can be cleaned with very fine wet and dry paper. The pic below shows the brass bush stuck on the shaft – that was the first motor I dissembled and the others I managed to keep the bush in the housing be cleaning the shaft first before I removed it. There are some very fine washers on either side of the shaft, be careful not to loose these and or forget to put them back on when putting it back together.

Heater motor commutator

My favourite method of rust removal is soaking in vinegar. It’s a method that requires very little effort and cost,  500ml of vinegar is only 20p at Aldi, so I buy 10 at a time! I submerged the rusty cases and left them for two days, then I scrubbed them under a tap with a washing up scourer, then left them to soak for another day. On the third day, after another scrub the parts are all back to clean metal ready for priming.

vinegar rust removalvinegar rust removalvinegar rust removal

vinegar rust removalvinegar rust removal

I also had a new heater motor kicking about that are made by Clayton Heaters Ltd. It is a Canadian made motor that is a direct replacement for the original Smiths motor. It’s much better made than the originals and so I’ve used this motor with one of the new galv snail cases. The Clayton Heaters part number is M1210 and Clayton Heaters sell them for £67.80 inc vat plus shipping. I got this one from a job lot of parts I bought some time ago from a local farmer, only cost me £30 for the lot including an engine! Here’s the finished one with the Clayton motor – this one’s now been sold but I’ve still got a few more to finish with the cleaned up Smiths motors and new wiring. I’ve also fitted one to my 109.

Series 3 Heater motor

New bulkhead vent seals

Today I’ve replaced the vent seals and also freed up the mechanism that opens and shuts the flaps, they were both partially siezed and not opening properly. The below pic shows the flap as far as it would open before I had a look at the mechanism(!):

Bulkhead vent flap

I managed to force it open a little wider so I get to the two small bolts that secure the flap to the opening mechanism and removed the flap. Below with the old seal:

Vent flap seal

I removed the opening mechanism by undoing the two screws that hold the lever to the dash and pulled out the mechanism which was seized solid. I managed to loosen it up with some WD40. To work properly all three pivots should be moving easily.

Vent opening mechanism

I removed the old seal and cleaned up the vent surround for the new seal. I have used seals made by Allmakes (MUC4299) which are far superior to other pattern seals. I’ve also got a set of Allmakes one piece door seals to go on at some point. I used a bead of clear silicone to secure the seal in place and closed the flap and left it to cure.

As you can see in the pic below, the flaps are now opening and shutting fully with ease. The seals are a good fit and water tight. When the silicone has fully cured I’ll remove the flaps again to clean up and paint them.

 opening bulkhead vent flap

Series 3 Land Rover Heater/Dashboard

Everybody moans about the the lack of effective heating in a Series Land Rover, but there are some simple things you can do to make it better. I’ve only ever had a minimal amount of air coming up through the demisters, but a healthy amount coming from the dash vents and for a while I stuffed a sock in both dash vents to improve the demisting! The heater controls at the end of the dash have never made any difference to air flow.

When I finally got round to investigating all became clear once I removed the dash and removed the vinyl cover (see photos below). There are 15 or so tiny screws holding the top cover onto the tin dash and these tend to rust badly along with the rest of the dash so may have to be drilled out. Once i opened it up I could see the mechanism that directs the airflow to the dash vents or demisters was rusted solid. Also the cables that are supposed to control it were  rusted into their sleeves. This is a very common problem on the S3 dash and if your heater controls aren’t working then this is why. If you don’t get much in the way of airflow then check the corrugated pipe from the blower to the matrix as these split easily, there is also a foam seal between the matrix and bulkhead that could be missing or leaking, also a seal between the bulkhead and heater box in the dash. If they’re all ok then your dash is probably a rusty mess behind the vinyl cover!! when all these are in good order then the series heater fan should actually suffice.

Series 3 Dashboardseries 3 dashboard3 dashboard

Removing the dash is a simple process of unscrewing the screws around the outer edges but there are also 2 bolts at the back that are easy to miss. These screw into a captive nut in the bulkhead and can be difficult to remove as the nut tends to corrode and spin, have circled where they are in this photo:

Series 3 Dashboard rear bolts

I managed to source a dashboard that was in better condition (tatty but no serious rust!). I stripped it down, wirebrushed as much surface rust off as possible and painted it in black hammerite. It’s not an amazing paint job but then nobody will see it anyway. I decided to remove the air diverter controls altogether as I’m not bothered about dash vents, only the demisters,so have blanked off the dash vents with some ally sheet that I had lying around. I’ll replace the covers so it looks correct.

Have got a new dash heater box to bulkhead seal gasket to fit (MTC6871) so there shouldn’t be any more air leaks. I’ve also bought 2 x new rubber gromits that the demister pipes fit into as the old ones were split (346785)

Land rover Series 3 DashboardLand rover Series 3 DashboardLand rover Series 3 Dashboard

Series 3 Dashboard

Series 3 Dashboard

The dash end wiper motor cover was also badly corroded so found another on eBay cheaply, it’s the same part from the Series 3 dashboards right up to the TD5 Defenders so there are plenty about. I got a TD5 cover and it fits perfectly.

Series 3 Wiper Motor Cover

Series 3 Wiper Motor Cover – same part used up to Td5 Defenders

series 3 wiper motor cover

The dash is now back on the vehicle and the movement of air is more than enough, it’s not that far from my Octavia Estate so goes to show when the system is in good shape the standard heater system is ok.