Heater oddities
Discussion
Hello
Been having a tinker this morning on the wedge to see if I can get the heater working properly. When I have the controls set to the windscreen, I get nice warm air coming out the windscreen vents, and also a bit of cold air coming from the dash vents. When I move the controls over so that air should be coming out both sets of vents, I get a nice cold blast of air coming out the dash, whatever I do, the air from the dash is always cold, no matter where the temperature dial is set to.
I have started to take things apart, seeing if I can get access to the air box/heater matrix area to see what's going on, as I suspect a control flap or something has come loose, so air is not being directed as it should.
After taking out the radio, and the panel with all the switches on, all I can see is a grey plastic box that I assume hides all the workings of the heater system, and the coolant pipe going in and out (both pipes are hot). The question is, how do I get at the rest of it? Is it a dash out job? I am hoping that if I can get to it that it will be a nice easy fix. Or is it something that's not worth the hassle, and I should just live with???
Cheers!
Been having a tinker this morning on the wedge to see if I can get the heater working properly. When I have the controls set to the windscreen, I get nice warm air coming out the windscreen vents, and also a bit of cold air coming from the dash vents. When I move the controls over so that air should be coming out both sets of vents, I get a nice cold blast of air coming out the dash, whatever I do, the air from the dash is always cold, no matter where the temperature dial is set to.
I have started to take things apart, seeing if I can get access to the air box/heater matrix area to see what's going on, as I suspect a control flap or something has come loose, so air is not being directed as it should.
After taking out the radio, and the panel with all the switches on, all I can see is a grey plastic box that I assume hides all the workings of the heater system, and the coolant pipe going in and out (both pipes are hot). The question is, how do I get at the rest of it? Is it a dash out job? I am hoping that if I can get to it that it will be a nice easy fix. Or is it something that's not worth the hassle, and I should just live with???
Cheers!
That's the way it's designed (at least on the two '86s and an '89 that I've pulled apart).
Cold air only to the face vents; and if you want hot air to go to the screen or your feet you have to close the face vents otherwise the fan won't push the air through the heater matrix, it'll take the easiest route instead.
Cold air only to the face vents; and if you want hot air to go to the screen or your feet you have to close the face vents otherwise the fan won't push the air through the heater matrix, it'll take the easiest route instead.
The Hatter said:
That's the way it's designed (at least on the two '86s and an '89 that I've pulled apart).
Cold air only to the face vents; and if you want hot air to go to the screen or your feet you have to close the face vents otherwise the fan won't push the air through the heater matrix, it'll take the easiest route instead.
Different in my SE, I get hot and cold air through the face vents. Never pulled the dash apart though so no idea what it looks likeCold air only to the face vents; and if you want hot air to go to the screen or your feet you have to close the face vents otherwise the fan won't push the air through the heater matrix, it'll take the easiest route instead.
Been having a it of a search around, and found this topic http://www.pistonheads.com/gassing/topic.asp?h=0&a...
What I have looks very very similar to what was taken to bits here, and as the pictures with the back of the air box show (from what I can see at least), then there is never going to be warm air from the dash vents as there is nothing to direct the air over the heater matrix and up to the dash vents. Seems like some people got a decent in car heater and others got a bit of a naff one.
What I have looks very very similar to what was taken to bits here, and as the pictures with the back of the air box show (from what I can see at least), then there is never going to be warm air from the dash vents as there is nothing to direct the air over the heater matrix and up to the dash vents. Seems like some people got a decent in car heater and others got a bit of a naff one.
If it works..Leave it!!..You have been blessed....However i do think the heater set up does need an upgrade..I had something in mind which incorporated a 12v 4" fan to just pull fresh air into the cabin through the cold air vents but close them off on the existing unit..Then check the housing flaps and gasket/seal and pipework for leaks and fitment as i was still going to use the matrix for warm/hot air..I was thinking of a replacement fan motor for the old unit....Cheers..Ziga
Hi
The heater/air system on a wedge changed over the years of production, but the what ever system they used it stayed the basic same system!
It depends on the year of production how the car gets fresh/air into the car/heater. From there it sends it (Depending if the system is working) to windscreen vents/face vents or to the footwell vents!
On the early cars the air is drawn in via a vent in the bonnet into a vent hole (Or holes if it's a real early car!)
It then goes past the fan/or fans into the heater box (Best name for it I can think off)
Early bonnet vents,
Early twin air vents.
Early 350i bonnet vents.
Early 350i air vent.
On later cars TVR changed the design so fresh air for the heater system was drawn into the system via the drivers window. (It realies on it being open) into the fan area via a hole in the drivers footwell, then into the heater box.
Late type bonnets no air/heater vents.
Series 3 280i.
Series 2 350i etc.
400/450 & SEAC
Look no air vents in engne bay!
Late car with no air vent but a heater duct in engine compartment!
Then the last cars like the 450SE or SEAC had no heater duct at all in the engine compartment.
The air what ever system they used was draw into the heater box from there it either gets heated by the heater switch being put to hot, which opens a valve which lets water into the heater rad. If you want cold air turn lever to cold, the valve is closed so no hot water gets to the rad. If you want the air to the screen vents move the lever to the screen postion and a flap moves in the box which diverts the air to the postion the lever is placed.
This is how this very basic system works, it all realise on every thing being adjusted correctly.
The later car had a problem as there was no easy way for fresh air to get into the system, some owners even altered their system to try and improve the air flow.
A 280i were some owner has made an air vent in the engine compartment to get air into the car, rather than get air from the window via the vent in the footwell!
I have found that to get the system to work its down to adjusting things so they turn the hot valve on and off to agree what the lever postion shows. The same goes for the airflap.
All the fan does is increase the flow that's all!
The early cars had a type of forced air via the bonnet vents but TVR did away with them for what ever reason, I will leave you to decide on that!
The problem with the fresh air on the later cars is down to the owners how you improve that!
Leave the window down a bit or drill holes in the heater system in the engine compartment to get air in, but this can also allow fumes in, so do what ever suits you!
Andy
The heater/air system on a wedge changed over the years of production, but the what ever system they used it stayed the basic same system!
It depends on the year of production how the car gets fresh/air into the car/heater. From there it sends it (Depending if the system is working) to windscreen vents/face vents or to the footwell vents!
On the early cars the air is drawn in via a vent in the bonnet into a vent hole (Or holes if it's a real early car!)
It then goes past the fan/or fans into the heater box (Best name for it I can think off)
Early bonnet vents,
Early twin air vents.
Early 350i bonnet vents.
Early 350i air vent.
On later cars TVR changed the design so fresh air for the heater system was drawn into the system via the drivers window. (It realies on it being open) into the fan area via a hole in the drivers footwell, then into the heater box.
Late type bonnets no air/heater vents.
Series 3 280i.
Series 2 350i etc.
400/450 & SEAC
Look no air vents in engne bay!
Late car with no air vent but a heater duct in engine compartment!
Then the last cars like the 450SE or SEAC had no heater duct at all in the engine compartment.
The air what ever system they used was draw into the heater box from there it either gets heated by the heater switch being put to hot, which opens a valve which lets water into the heater rad. If you want cold air turn lever to cold, the valve is closed so no hot water gets to the rad. If you want the air to the screen vents move the lever to the screen postion and a flap moves in the box which diverts the air to the postion the lever is placed.
This is how this very basic system works, it all realise on every thing being adjusted correctly.
The later car had a problem as there was no easy way for fresh air to get into the system, some owners even altered their system to try and improve the air flow.
A 280i were some owner has made an air vent in the engine compartment to get air into the car, rather than get air from the window via the vent in the footwell!
I have found that to get the system to work its down to adjusting things so they turn the hot valve on and off to agree what the lever postion shows. The same goes for the airflap.
All the fan does is increase the flow that's all!
The early cars had a type of forced air via the bonnet vents but TVR did away with them for what ever reason, I will leave you to decide on that!
The problem with the fresh air on the later cars is down to the owners how you improve that!
Leave the window down a bit or drill holes in the heater system in the engine compartment to get air in, but this can also allow fumes in, so do what ever suits you!
Andy
Edited by Mr Tank on Wednesday 9th January 21:18
Mr Tank said:
On later cars TVR changed the design so fresh air for the heater system was drawn into the system via the drivers window. (It realies on it being open) into the fan area via a hole in the drivers footwell, then into the heater box.
I think you're over-describing this arrangement: as used on my car, it takes air from the driver's footwell and warms it up. Nothing to do with 'fresh' air, it's simply known as a recirculating heater and was always popular with kitcar builders as it kept things simple, warmed the cabin up faster and left the fresh air function to dropping the roof or opening a window.I think the problem TVR always had was in keeping the fumes from the engine bay out of the fresh air vents, that's why they largely gave up. They could have used a length of flexi (Hoover hose!) down through one of the wings to the nose but of course that would have had a cost/time penalty.
I pulled the dash out of my 350 the year before last to access the heater box, its very primitive and the air diverter if you can call it that was like a very flimsy spatula which looked like it had been cut sing Neds jaws and was deffo not a provision piece of engineering. I remade the box in the end with future access to the matrix an option without having to pull the dash out, it seems to work ok so I'm happy. 
It has nowt to do with them tubby telly thingys.
It has nowt to do with them tubby telly thingys.
This is the 350i heater I ripped apart (see the SEAC rescue thread...)
The heater matrix air flow goes though this small aperture; the slider/dial on the dash controls the position of the 'paddle' thingy to either bypass the heater matrix or go through it...
The other dashboard slider/dial controls this paddle, the rear aperture in the pic goes to the screen vent and the front aperture in the pic goes to the footwell vents. when both apertures are shut off the flow can only go to the face vents (which by-passes the heater matrix too).
Quite clever, but Heath Robinson comes to mind!
The heater matrix air flow goes though this small aperture; the slider/dial on the dash controls the position of the 'paddle' thingy to either bypass the heater matrix or go through it...
The other dashboard slider/dial controls this paddle, the rear aperture in the pic goes to the screen vent and the front aperture in the pic goes to the footwell vents. when both apertures are shut off the flow can only go to the face vents (which by-passes the heater matrix too).
Quite clever, but Heath Robinson comes to mind!
Wedg1e said:
I think the problem TVR always had was in keeping the fumes from the engine bay out of the fresh air vents, that's why they largely gave up. They could have used a length of flexi (Hoover hose!) down through one of the wings to the nose but of course that would have had a cost/time penalty.
IanI think the whole thing is down to cost.
If you look at the vent and the bonnets.
The factory reduced the vents for cost reason, and simplification of production etc.
To have as you suggested "used a length of flexi(Hoover hose!) down through one of the wings" is a very simple idea and cheap compared with say the work to produce the bonnet used for the first 350i's.
I just think they were doing things to just simplify production to save money!
The heater system was just a necessity they had to have, but they spent so little on the design etc we got a very simple system which barely worked no matter what type you had!
Andy
Mr Tank said:
I think the whole thing is down to cost.
Andy
Undoubtedly. I think cost was king the whole time. In the case of the heater I think they designed the rest of the cabin and lashed-up the heaters to fit the available space. The early ones were made with two halves in GRP, bonded together with all the components trapped inside. The later ones were plastic-welded from polyprop or similar sheet; essentially they scored the sheet and folded it to get the basic shape then tacked bits on. By comparison the heater in the Esprit was well thought-out and engineered - and that was a lash-up too! Twin fan motors, hot and cold air simultaneously, proper demist...Andy
This is great don't you just love the design and the fish slice technology! And they say the man in a shed solutions are dead!! Martin I meant to say that I had mine out about 5 years ago and sorted out the wheel action as it was corroded at the time. Cleaned mine and added copious amounts silicone grease. My problem was the matrix, it was full of silt and crud. Had it re-cored by a local radiator man and it has worked since..! (sign of the cross and touches wood) as this will be the kiss of death! Got to say that getting air out of the coolant system as also been straight forward since...
Chris
Chris
Question: Do you use your wedge all year round or is it tucked up in a garage for the winter months?..In which case you dont need to worry about the heater in your wedge..Just get one for the garage!..I drive mine all year round so if i want cool air it must mean its hot outside in which case off comes the roof!..When its cold outside then i would like to have hot air..My heater does actually give warm/Hot air from windscreen and face vents..(It must be leaking)..Even though my fan only works on high speed..There has been times when i have been out and it's rained heavy and the screen has instantly misted up..Mine does demist albeit very slowly and with the help of the drivers side window open a little and a microfibre cloth.. However this is something that is on my upgrade list..The major factor for me is removing the dash but when i get round to it then i might consider a replacement unit or maintaining the old one..Also dont forget that the bigger the fan is then the cooler it will make the hot air that it's pulling/pushing..A new heater motor and a check of the seems and control flap seals might yield a good system..Cheers..Ziga
PS:I can vouch for chris..When he turned up on saturday at the park and opened his door it was like a mini heat wave..
..(Mini heat wave)
Unit replacement:
http://www.google.co.uk/url?sa=t&rct=j&q=c...
PS:I can vouch for chris..When he turned up on saturday at the park and opened his door it was like a mini heat wave..
..(Mini heat wave)Unit replacement:
http://www.google.co.uk/url?sa=t&rct=j&q=c...
Re Fan - mine stopped working on the slower speed and it turned out to be the resistor under the dash that had failed. It did actually have 3 contacts slow, medium and fast so I just connected the wire to the unused medium contact and now have medium and fast settings instead of slow and fast.
Interesting about the fan speed, I might look at that; assuming the motor is rated at 12 volts?
Chris, you mention you had the heater matrix recored, did they do it in the original style of tube/fins or did they use some sort of high efficiency matrix? I also noticed your car has entry and exit pipes for the heater both on the passenger side; my car has one inlet on the passenger side and outlet on the driver's side. Did your heater matrix have cross flow or a U-flow water connections?
Chris, you mention you had the heater matrix recored, did they do it in the original style of tube/fins or did they use some sort of high efficiency matrix? I also noticed your car has entry and exit pipes for the heater both on the passenger side; my car has one inlet on the passenger side and outlet on the driver's side. Did your heater matrix have cross flow or a U-flow water connections?
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