Replacing Automated Heating System by retrofitting manual two lever system.

[keithwren]

I've come to the end of my tether with the existing system and want to replace it with the earlier two lever system. Does anyone have any recommendations who can do this work for me.
Thanks.

 

[barrygale]

Design 911 in Essex would be able to do this (they have a full restoration workshop)

 

[T911UK]

Its really not that difficult to do this yourself if you are half decent at DIY

 

[keithwren]

Thanks guys. I have fiddled with fixing it in the past but thought I would get it done professionally. The cars has just come out of a full bodywork restoration after being off the road for 20 years and I must admit I have forgotten how I got it working in the past. My memory vaguely tells me you can disconnect the the rod in the automatic heat control box from the ball joint and use the red lever to open and close the heat exchanger heating valves (which are now new) but not sure if the fan will work from the dial. Any thoughts on this??

 

[T911UK]

You're halfway there, normally the control box is removed completely as is the fan and the ductwork in the engine bay

Then 2 small ducts are used to connect the engine cooling air to the heat exchangers. A slight mod on the handbrake heater lever and you have full control of the 2 flapper boxes via the red knob

 

[keithwren]

Thanks, the information is very helpful. I will do some more investigation on getting the parts I need and give it a go!!!

 

[T911UK]

This is the duct set;

911 Heater Backdate Duct Set Left & Right Aftermarket

90110632102 & 91110632700 93016032102 These reproduction fan housing outlets are replicas of the early 1965-74 style. Made from sheet metal and powder coated black for longevity these are perfect for early heat exchanger & header conversions. Fits all 911 1965-89 fan housings. As these are...

type911shop.co.uk

Then you just need some flexible hose to suit, I got mine from ebay, you only need 1 metre

 

[geedee]

Been a long time since I owned my wonderful SC. I guess much depends upon the expected performance from 80`s air cooled ICE heating systems compared to the increase in tec and comfort levels available from today`s water cooled ICE...?

For me, the frustration was mostly de icing, until I found that just cracking the window open a tad seemingly increased the flow of hot air into the cabin as the fan was not then trying to pressurise the cabin.... Worked for me...might work for you.. fingers crossed.

 

[keithwren]

Thanks for the info on the duct set and think I'll make it a project for later in the year as intend to have the Targa roof off most of the time, weather permitting.

Its when it is raining that is the pain as the screen mists and I end up with nasty marks on the screen where I have had to wipe it with a cloth. Can't stand a smeared windscreen!!

 

[keithwren]

She’s nothing special but have owned her since 1988 so thought it about time she had some TLC!!

 

[T911UK]

Is your fresh air fan working? That does most of the defrosting of the screen. if its not working you will be in trouble in the winter!

 

[keithwren]

The car is currently being snagged by the restorer and I have pointed out the fresh air fan is not coming on when I move the lever on the dashboard so hopefully they will fix that. Must admit I didn’t appreciate/remember that the front fan is instrumental in clearing the screen, I’ve just been focusing on the heating and engine bay fan so thanks for the info.