Spitfire heater blower

[1969Mk3Spitfire]

Caught out in the rain yesterday, first time since I bought my Mk3 Spitfire.  The heater blower has never worked and fixing hadn't made the jobs list. That changed when the front screen steamed-up 😒. 

Any helpful tips to go in search of the problem? Access to the rear of the switch and the motor doesn't look simple.  How do you gain access?

Thanks in advance for any pointers.

 

[Chris A]

On my 13/60 the fan stopped working some months ago. First step was to connect fan direct to battery, the fan ran so not the fan. Then confirmed the ignition switch was passing current to fan switch. So fan switch was the problem. I had noticed the fan switch had more then one set of connectors. Swapped from one set to the other and all was fine. 

Ok so the two cars might have completely different switches but the method of tracking would still work.

[Colin Lindsay]

Assuming it's got the same three fuse unit as the GT6 of the same era and everything else on that fuse - the top fuse with the green wire - works then it's not the fuse.

It's a simple power-to-earth system; power goes from the green wire at the fuse box (via the stabiliser) to the switch; the switch then permits power to the blower and then on to earth. You can try putting direct power to the blower motor; there are only two wires, I think green and black, so black is earth and putting 12v power to the green wire will tell you if the motor spins or is dead. Bypassing the switch by connecting the two cables together from the switch terminals will tell you if the switch is dead, but only after you've confirmed that the blower spins when powered up. 

Access will be through the passenger side glovebox so remove the glovebox and the padded front rail if you need to, to give more room, then try to identify the blower motor and the green wire to it. There'll be a bullet connector close to the motor to which you can put direct power from a battery - just be very careful with anything electrical not to short anything out; you can also put power to the same wire at the switch which may be easier to access. The black earth wire will be screwed to something metal close by; often it's just a poor earth that stops things from working so unscrew, clean up, and replace, and if in any doubt try a different earth point. The switch can be removed by unscrewing the silver bezel and pushing through.

If the motor is dead then sadly it's a more complicated job to remove and replace, so here's hoping...

 

[Peter Truman]

My Mk2 Vitesse fan switch failed just last month it was only 52 years old, why did Triumph use double pole switch, the internal spring had disintegrated. I simply replaced it with a single pole on off Lucas switch the Vitesse is easily accessed thro the ash tray on top of the dash.

If I remember correctly the daughters Mk2

Spit has the same single pole switch

[1969Mk3Spitfire]

Many thanks for the replies.

I've removed the passenger side glove box and the switch.  I have 12v and bypassing the switch doesn't fire-up the motor.  A separate 12v supply into the 2 wires doesn't make it work, either.

I've pushed the car out of the garage such that I can open the doors but it's raining so I'll test it again later using decent electrical contacts/patch leads, rather than poking bare wires into spade connectors.  The two wires to the motor are open circuit so it's not looking good. 

Does the motor easily separate from the heater assembly?

[Mad4classics]

You really need to make sure the motor is the problem first!

Unfortunatly on the mk3 the motor is held by nuts spun onto the motor through bolts which are under the fan inside the casing; so you need to remove the heater box remove the small self tapers holding it together and carefully remove the fan to get to the motor mounting nuts. (Don't break the fan at this point because it's likely the motor shaft is rusted and the fan will be well and truly stuck on - I did and had to buy a new fan blade!)

One of those simple jobs that just spirals since the tacho and speedo cables pass through the heater box and you need to drain the cooling system and remove the tunnel to get access. The heater is held by the four bulkheld bolts under the bonnet.

I had to remove mine because the heater matrix was leaking all over the tunnel. I took the opportunity to replace the motor brushes at the same time because they were quite worn. I think you can get reconditioned motors from the usual suspects.

If it is your motor it may be just the brushes have worn out and need replacing. But as I said at first  -make sure it's not something else other than the motor. The heater was an optional extra after all.

David

[Colin Lindsay]

Can you access the fan blades and spin them with something, just to make sure they're not stuck in place, and the motor can't overcome the obstruction?

[1969Mk3Spitfire]

Thanks, David, that’s depressing but helpful.

Thanks also Colin, any suggestions as to how I may be able to spin the blades?

A multimeter shows open circuit between the positive (from the switch) to the earth point. I’ll remove the earth connection and check the wires directly tomorrow, weather permitting.

The 51 year old switch definitely doesn’t work.

I’ve had the tunnel out once to do the gear change bushes. I have an oil leak which I think is coming from the speedo cable connection so I’m psyching myself up to remove it again.

[Colin Lindsay]

2 minutes ago, 1969Mk3Spitfire said:

Thanks also Colin, any suggestions as to how I may be able to spin the blades?

First thought that came into my head was to blow air into them, maybe from an air gun and a compressor, if you can get access, maybe one of those long-nozzled air guns?

[Mad4classics]

12 minutes ago, 1969Mk3Spitfire said:

Thanks, David, that’s depressing but helpful.

Honestly, it's not as bad as it sounds.

Spinning the blades might help get it going as Colin suggested if it's just gummed up, but access is difficult; the only way is through the side footwell flaps which means forcing air through the heater matrix fins!

David

[DerekS]

A daft suggestion here, don't even know if it's viable, remove all the outlet ducts and tape them up, except for one and put a vacuum cleaner hose onto to it... this is just off the top of my head so apologies if it isn't workable!

[1969Mk3Spitfire]

Thanks again to you all, much appreciated.

I've tried blowing and I've also tried the vacuum cleaner but no eureka moment, sadly.  I've reached the point of no return but I'm saving it for another day................

So, left glove box off, ducts off, tunnel off (still can't find the oil leak 😢).  Coolant drained, heater hoses removed and pipes plugged with rag ends. 

Next job is to remove the 4 bolts from the bulkhead.

Then what?

How do I deal with the tacho and speedo cables? Pull them through from the engine bay?

Thanks in advance.

[Mad4classics]

It's much easier to remove the rubber grommets the cables pass through on the engine bulkhead side and from the footwell side of the heater box ( assuming a PO has not left them off - it blows air out round the cables if their not fitted) first - taking the ones at dash end right off. Then just pull through to the engine bay.

You'll need to unclamp the choke and heater cables from the drivers side of the heater.

If doing this single handed wedge up the heater box with something soft over the gearbox for it to drop on when you undo the bolts.

 

David

[thescrapman]

Then once done, look for a better motor.

the is one from a Smart 4/2 that fits, also aMustang one I beleive.

maybe also Micra, but that may be a different car.

[Paul H]

9 hours ago, thescrapman said:

Then once done, look for a better motor.

the is one from a Smart 4/2 that fits, also aMustang one I beleive.

maybe also Micra, but that may be a different car.

The Micra fits the Vitesse 

Paul 

[Colin Lindsay]

58 minutes ago, Paul H said:

The Micra fits the Vitesse 

Paul 

And the Herald. Not so easy to get at on the Micra; it's under the dash, which surprised me when I went looking for some - they weren't in the engine bay! The motor looks the same - between Spitfire and Herald / Vitesse - but the Spitfire fan blades are shallower, so they'll need swapped over.

[1969Mk3Spitfire]

I've still yet to remove the heater unit but this background info on suitable alternatives is very helpful.

There is open circuit between the two wires so it could be that the brushes are stuck open.  Once I've removed the heater matrix, is it possible to remove the motor housing to clean the commutator and brushes?

Are those quoted as replacements a like-for-like swap?

[Colin Lindsay]

1 hour ago, 1969Mk3Spitfire said:

Once I've removed the heater matrix, is it possible to remove the motor housing to clean the commutator and brushes?

I'd like to think that it's the same three-screw fitting as on the Herald, so it will simply unscrew and lift out. Be careful with the sealing gasket; I'm not sure if they're available any more.

[Mad4classics]

OK, it's a really bad picture (head in footwell taking it), but on the shallow MK3 Spitfire heater style with moveable footwell side flaps the motor is held on by nuts spun on to the two through bolts that hold the motor together. These are under the fan inside the casing.

You need to release the central fan compression nut and slide the fan off the motor shaft to get to them. Once the two nuts are undone the motor is free and you undo the additional nuts on the through bolts to break the motor into two halves. ( You can just see the lower one of these as a nice shiny new nut between the motor and the casing from when I took mine apart).

I think the brushes were 1/4" square from memory - check.

David

[1969Mk3Spitfire]

I've now removed the heater matrix and removed the motor.  It's a Smiths FHM 4432/01 with date code 08 68 date code so it's most likely the original fitment.

Just two nuts to separate the two halves.  It didn't look pretty inside.  The very small wire from one of the brushes had broken so I thought that it may be a relatively simple fix. I soldered the wire and now have 12v at the brushes but still no sign of life.

I've looked at Micra, Smart 4/2 and Mustang heater motors but none look the same as the one I've just removed.

I've emailed a number of potentials for new, used or service exchange, found via Google searches.  

Any other thoughts to find one?

 

[Mad4classics]

Since I last looked at this, the supply seems to have dried up a bit.

If you fancy a motor brand new shipped from America however.

https://europeanpartscompany.com/armstrong-siddeley-triumph-spitfire-austin-gipsy-heater-blower-motor/

There's a couple of second hand complete heater units on ebay right now. eg...

https://www.ebay.co.uk/itm/Triumph-Spitfire-Heater-Unit-/254703599390?nav=SEARCH

There's no garantee you'd get a working unit - will need attention I think.

The MK3 heater seems to be one of Triumphs famous undocumented changes because the later box in the link above actually takes the matrix listed for the MK4 and a different bulkhead gasket which I ended up making myself because I couldn't find one. (cardboard template in image compared to MK1-3)?

Check dimensions here.

http://www.motoradsonline.co.uk/products/Triumph-Spitfire-Mk4-Heater-matrix-.html

A search of the second hand parts suppliers perhaps.

Where the heater is situated limits the choice of alternatives if you go down that route. You don't want to foul the back of the dashboard or encroach into the radio space assuming you have/ want one.

David

 

[Colin Lindsay]

Looks like the same motor, maybe the fan fitment is different?

https://www.ebay.co.uk/itm/Classic-SMITHS-7044FH-Heater-Blower-Fan-Motor-Triumph-Jaguar-Lotus-MG-12-Volts/333286956314?hash=item4d99735d1a%3Ag%3AApQAAOSwlqtdRalU&LH_ItemCondition=3000

This one for £8.20:

https://www.ebay.co.uk/itm/Triumph-Spitfire-Gt6-Heater-Motor-VGC/333704794526?hash=item4db25b119e%3Ag%3AFiEAAOSwcylfS~nJ&LH_ItemCondition=3000

This one should be the correct period for the Mk3:

https://www.ebay.co.uk/itm/TRIUMPH-GT6-MK1-MK2-MK3-SMITHS-HEATER-BLOWER-FAN-MOTOR-FHM5342-01-RV/164347578420?hash=item2643e10834%3Ag%3AorAAAOSwq2Nd3BWP&LH_ItemCondition=3000

[Mad4classics]

13 minutes ago, Colin Lindsay said:

Looks like the same motor, maybe the fan fitment is different?



https://www.ebay.co.uk/itm/Classic-SMITHS-7044FH-Heater-Blower-Fan-Motor-Triumph-Jaguar-Lotus-MG-12-Volts/333286956314?hash=item4d99735d1a%3Ag%3AApQAAOSwlqtdRalU&LH_ItemCondition=3000

That looks as if it could be made to fit, especially if the alloy flange part is removed.

The early motors are all 2 bolt fixing - no flange like the others. The first link I posted above shows the actual motor .

The MGB single speed motor could also be made to fit if you ignored the three hole mounting flange half way along the body and used the motor through bolts

David

[Colin Lindsay]

I thought, looking at the body, that they were all very similar so supposed the slight variations in fan size may account for the different model numbers? Then again they may all have the same fixing, so it's hard to guess. I just searched eBay for 'Triumph Heater' then narrowed it down to Car Parts, UK, and Used, and got plenty, so there may be the correct version out there.

[Mad4classics]

Ok, either the motor needs to be modified to fit the mount or the box to fit the motor. Unlike all later variants the early heater box is just a very simple two fixing holes - not flange mount.

So some mods required - the holes for the speedo and tacho cables are quite close.