Griff Vent System
Discussion
Right - the ventilation system works like this:
In the passenger wing (yes, in the wing) is the blower fan. This draws fresh air from the outside (in the wing). If you rotate the recirculate dial it opens and closes a flap in the passenger footwell on the left that lets the fan draw air in from the cabin instead of outside. The dial is proportional so you can have the flap open part way. You can see the flap in action if you remove the passenger kick panel/carpet and look to the left of the battery. It is operated by a servo motor.
That's the recirculation element.
This fan feeds a black plastic box behind the glove box. This box contains the heating element, and also a servo motor that redirects air. When the air is set to "down" then the box sends the air to the left most vent via flex piping - the one left of the passenger - this is the default action. This is the only vent that blows hot air from the heater box (other than the footwell vent - same box).
When you select "up" or demist, the air is redirected to the back of the dash to the dash top/ windscreen vents along the top.
To get hot or cold air on the passenger's feet you simply manually open the vent on the bottom of the black heater box under the dash. This now means you are sharing the hot air with the dash vent.
The next vent is the one on the dash panel to the left of the gear stick. This is piped directly into the wing and does nothing but allow fresh air to enter the cabin. It is not powered, or heated. It is simply "fresh air".
The vent on the dash panel on the right of the gear stick is linked to a fan by the driver;s right leg. This is controlled by a dial under the steering wheel cowling and purely blows cold air.
So you have three main vents plus the footwell vent
Left vent - hot or cold air - can be redirected/shared to passenger footwell. Can be fresh or recirculated via flap.
"Middle" vent - fresh air only.
"Right" vent - cold blown air only.
The left (main) blower, servo motor for the recirc flap, and servo motors for hot/cold up/down are all controlled by a black heater control box in the dash which is in turn controlled by the dials by the gear stick.
If you need any specific pictures please ask (pm me so I don't miss your request) as I'm putting the dash back on in about a week or so (by dash I mean the whole thing, not just the walnut insert)
In the passenger wing (yes, in the wing) is the blower fan. This draws fresh air from the outside (in the wing). If you rotate the recirculate dial it opens and closes a flap in the passenger footwell on the left that lets the fan draw air in from the cabin instead of outside. The dial is proportional so you can have the flap open part way. You can see the flap in action if you remove the passenger kick panel/carpet and look to the left of the battery. It is operated by a servo motor.
That's the recirculation element.
This fan feeds a black plastic box behind the glove box. This box contains the heating element, and also a servo motor that redirects air. When the air is set to "down" then the box sends the air to the left most vent via flex piping - the one left of the passenger - this is the default action. This is the only vent that blows hot air from the heater box (other than the footwell vent - same box).
When you select "up" or demist, the air is redirected to the back of the dash to the dash top/ windscreen vents along the top.
To get hot or cold air on the passenger's feet you simply manually open the vent on the bottom of the black heater box under the dash. This now means you are sharing the hot air with the dash vent.
The next vent is the one on the dash panel to the left of the gear stick. This is piped directly into the wing and does nothing but allow fresh air to enter the cabin. It is not powered, or heated. It is simply "fresh air".
The vent on the dash panel on the right of the gear stick is linked to a fan by the driver;s right leg. This is controlled by a dial under the steering wheel cowling and purely blows cold air.
So you have three main vents plus the footwell vent
Left vent - hot or cold air - can be redirected/shared to passenger footwell. Can be fresh or recirculated via flap.
"Middle" vent - fresh air only.
"Right" vent - cold blown air only.
The left (main) blower, servo motor for the recirc flap, and servo motors for hot/cold up/down are all controlled by a black heater control box in the dash which is in turn controlled by the dials by the gear stick.
If you need any specific pictures please ask (pm me so I don't miss your request) as I'm putting the dash back on in about a week or so (by dash I mean the whole thing, not just the walnut insert)
RogerDodger said:
...The next vent is the one on the dash panel to the left of the gear stick. This is piped directly into the wing and does nothing but allow fresh air to enter the cabin. It is not powered, or heated. It is simply "fresh air".
Perhaps TVR rigged the heating system differently in some cars because on my March 1999 Griff 500 both dash vents either side of the radio can be blown by the fan and have hot and cold air. RG
Great response and description of the system.
I don't have the driver's side blower in my 2000 Griff.
I think the first thing is to do is to look at the connections, ribbon cables etc and check good.
I am hoping it's not an ECU issue.
Photos would be good to identify components.
Thanks
A
Great response and description of the system.
I don't have the driver's side blower in my 2000 Griff.
I think the first thing is to do is to look at the connections, ribbon cables etc and check good.
I am hoping it's not an ECU issue.
Photos would be good to identify components.
Thanks
A
Does anyone have a similar description for a pre-cat Griff?
My project this weekend is to try and find out why it doesnt/didnt work.
The first thing I will do is read the manual. However, I remember from when I last drove it that while the fan worked, niether the temperature control nor the controls directing where tbe air was going to made a blind bit of difference. A similar text to the above will help. Unless it is the same, although the controls are different.
My project this weekend is to try and find out why it doesnt/didnt work.
The first thing I will do is read the manual. However, I remember from when I last drove it that while the fan worked, niether the temperature control nor the controls directing where tbe air was going to made a blind bit of difference. A similar text to the above will help. Unless it is the same, although the controls are different.
BD
I had a pre-cat and seem to remember this:
You have a rotary switch with three on positions to control the fan speed using resistors.
The two horizontal rocker switches control:
1.A servo motor + microswitches to stop travel on an up/down flap in the heater box.
2.A servo motor + microswitches to stop travel on a water flow control valve that controls the flow of hot water through the heater matrix.
Check wiring, servo motors, microswitches & adjustment, if any moving part has seized.
HTH
A
I had a pre-cat and seem to remember this:
You have a rotary switch with three on positions to control the fan speed using resistors.
The two horizontal rocker switches control:
1.A servo motor + microswitches to stop travel on an up/down flap in the heater box.
2.A servo motor + microswitches to stop travel on a water flow control valve that controls the flow of hot water through the heater matrix.
Check wiring, servo motors, microswitches & adjustment, if any moving part has seized.
HTH
A
RichB said:
Perhaps TVR rigged the heating system differently in some cars because on my March 1999 Griff 500 both dash vents either side of the radio can be blown by the fan and have hot and cold air.
Funny you shoudl say that because all it woudl take is to pull the pipe from the wing and join it with a Y piece to the left vent pipe and bingo! you have both working. No idea why they didn't do it on some cars. Mines a '96 
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