Griff heating

[Mags]

Sorry to keep asking questions but new ownership brings many new questions

I know the heating on Griffs is either hot, or very hot but I'm not convinced mine is working as it should.
I've looked through Steve Heaths excellent book on the heating section but it doesn't go into detail on what is happening when you fiddle with the switches (on a Griff 500)
Can anyone explain what each switch is actually doing? for example, I hear no motor noises when I twiddle the air control from external air to recuirculating and I hear and feel no difference to the air at all. I'm expecting some sort of flap to be moving to block out/allow external air through, but shouldn't I be able to hear or feel the difference?

Yesterday evening when it was getting colder, the heat setting seemed to make no difference at all to the temp of the air blowing through, is that really how it is? is it not possible to get anything other than hot air through the vents?

Thanks

Mags

[steve-V8s]

If you look in the passenger foot well, tucked up in the wing you should find a motorised valve and a motorised flap. The flap blocks or doesn’t block a hole. You may need to move a bit of carpet to see what you want. While you are down in the foot well take care not to knock the light switch (if you have one) into the on position. If you do the first thing you will notice, probably tomorrow morning, is a flat battery.

[Mags]

thanks, I'll take a look. So should I be able to hear this moving if the engine isn't running?

[steve-V8s]

Only just, on mine it is just a very gentle wirr.

[Rob_the_Sparky]

I figured out the heater control and got that working on mine but not the two controls on the bottom row!

The heater control is a potentiometer. There is another one on the motorised valve and when you turn the control the motor turns to the new position, basically following your control input.

There seems to be a number of ways this can go wrong:

On mine the potentiometer had fallen off the heater valve (!). Stuffed it back in and I (amazingly) can get both hot and cold air.

The heater valve potentiometer has no alignment lugs. As it the valve a simple ball valve unless the potentiometer is correctly aligned to the valve you get a "part open to fully open to part open" control or a "part open to fully closed to part open". I.e. either "warm to hot to warm" or "warm to cold to warm".

From what I've read most seem to suffer from the second problem. TBH having taken a look at how it is put together I'm not surprised...


Oh and it is a water flow control so it reacts quite slowly to control input as the water in the heater matrix changes temperature relatively slowly after a change in the control location. No instant reaction to control input like you get on an air flap type system that you get on most cars.

The other thing I have noticed is that the dash vents always seems cooler that the others and if you turn on the fan the dash vents turn off. Not sure why...


I'm sure someone with more experience will be able to help, as said I've not tried figuring out the lower rox of controls yet as seemingly they make no difference at the moment - although something certainly moves, or at least wirrs!

Rob

P.S. Only had my car since April

P.P.S. Do some searches, there are some old threads on here that I found very useful...

Edited by Rob_the_Sparky on Monday 26th October 17:17

[Mags]

Thanks Rob, Where is the heater valve you reffer to? Wouldn't hurt for me to take a quick look.

Mark

[HRG.]

Mags said:

Thanks Rob, Where is the heater valve you reffer to? Wouldn't hurt for me to take a quick look.

Mark

The HCV lives directly under the glovebox on the left hand side of the cockpit. Follow the two heater pipes and the wires and you'll soon find it and be amazed at just how professional the whole setup is

[clive f]

I got so fed up with the hot air only syndrome, I`ve put a valve in the pipework under the bonnet, at least I`ll not fry in the thing next summer.

[Mags]

HRG. said:

Mags said:

Thanks Rob, Where is the heater valve you reffer to? Wouldn't hurt for me to take a quick look.

Mark

The HCV lives directly under the glovebox on the left hand side of the cockpit. Follow the two heater pipes and the wires and you'll soon find it and be amazed at just how professional the whole setup is

Lol, I've already had to adjust my expectations on a few things regarding the quality and engineering. Its funny, I knew that I had to expect some 'character' but it still raises a smile, I found at the weekend that to change a lightbulb requires a tube of sealant, that was a suprise!
I can't imagine how some first time TVR customers must have felt when they swapped thier german sports cars for Trevs in the late 80's

[HRG.]

Mags said:

HRG. said:

Mags said:

Thanks Rob, Where is the heater valve you reffer to? Wouldn't hurt for me to take a quick look.

Mark

The HCV lives directly under the glovebox on the left hand side of the cockpit. Follow the two heater pipes and the wires and you'll soon find it and be amazed at just how professional the whole setup is

Lol, I've already had to adjust my expectations on a few things regarding the quality and engineering. Its funny, I knew that I had to expect some 'character' but it still raises a smile, I found at the weekend that to change a lightbulb requires a tube of sealant, that was a suprise!
I can't imagine how some first time TVR customers must have felt when they swapped thier german sports cars for Trevs in the late 80's

Why they couldn't enclose the whole affair, apply some plastic sleeving and then 'pot' the whole lot is beyond me.