Heater controls now stuck

[Kevinrpayne]

I have a GT6 and have noticed that the LH heater control that selects where the heat should be diverted to, is now largely stuck and has a significantly smaller range of travel than it once did. It goes about 50 % from side to side.  I’ve had a quick look under at the actual fan unit and can’t see anything obviously wrong. I’ve removed the cable and I’m pretty certain that the problem is internal to the fan box but don’t know how far the lever  should travel so hard to tell

looking at the Haynes manual it looks a bit of a nightmare to get out and when I do then the thick (foam?) washers/spacers don’t appear to be available any more so I’m reluctant about removing and then can’t refit

Is it really necessary to remove the gearbox tunnel to get the fan box out ? any suggestions as to what to do pre fan box removal and secondly where to get the material for manufacture of spare spacers from as shown in the pic that I’ve borrowed from Canley pts no 616627

thanks Kevin

[Josef]

Any sort of closed cell foam will do for the spacers. I’ve used pipe lagging for the round ones as it obviously comes in that shape. I don’t think the tunnel needs to come out, unless the heater box is considerably larger than the ones in the early Spitfires. Can’t comment on the internals I’m afraid as I’ve never looked at one of these. 

[Pete Lewis]

do make sure the outer cable clamps are not overtightened   

[Kevinrpayne]

Ah yes I have some insulation in the roof that will do thanks

 

Pete The outer clamps ? 
 

kevin

[johny]

= anything that clamps the ends of outer sheath of an operating cable and if done up too tightly may crush it so restricting the movement of the inner...

[Graham C]

Am I correct that this control operates the flaps in the heater, if So the the cable is attached to one flap and the other is moved via a stiff wire connecting the two flaps. Have you checked the flaps move freely and not got stuck due to corrosion on the pivots.Graham

Graham

[Kevinrpayne]

Thanks for this. The pivot turns about 50 % of its range so I concluded that the pivot in the heater box was ok 

I disconnected the cable at the dashboard end and tried moving it by hand and it didn’t move any more so presumed the problem was in the heater box. Don’t know if something has rusted off and dropped down to prevent full movement ? 
 

I didn’t do the other end of the cable but will do now. It started to look like a full day job and I didn’t have time Sunday night 

thanks kevin

[Graham C]

From memory the flaps should open fully, so add some oil and work them , you may have to undo the stiff wire clamp that joins them.  This will enable you to work them separately.

Graham

[Kevinrpayne]

Thanks. I’ll try that before I take anything out 

 

Kevin