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S4 thermostatic rad fan switch

PostPosted: Fri Apr 22, 2016 6:25 am
by lottex
I'm trying to keep my late S4 SE as original as possible. I have been advised that the original factory screw in to the top of the rad thermostatic fan switches have long since disappeared... Unless anyone out there knows otherwise! Most grateful .
Thanks, Pete

Re: S4 thermostatic rad fan switch

PostPosted: Fri Apr 22, 2016 9:37 am
by richardcox_lotus
There were 2 types - dealer fit into top hose for Kenlowe type fans, or an otter switch into radiator header on the opposite side of the inlet hose, for the cradle supported smiths-motor driven fan.

For an S4 I guess it'll probably be the latter. Otter switches are still available new but they don't look quite the same as they now have spade electrical fixings rather than the original pin. Also note they are a push in fit, rather than a screwin

Hope this helps

Richard

Re: S4 thermostatic rad fan switch

PostPosted: Fri Apr 22, 2016 9:47 am
by lottex
Thanks Richard, my car definitely has the latter switch-ie one that screws into the radiator header on the opposite side of the inlet hose. I do have the original switch but it's not working. I assume its a sealed unit that can't be repaired-unless anyone can suggest otherwise..?
As a plan B, to fit the later push in type, one images that the rad needs to be modified?
Thanks again, Pete

Re: S4 thermostatic rad fan switch

PostPosted: Fri Apr 22, 2016 10:26 am
by Certified Lotus
lottex wrote:Thanks Richard, my car definitely has the latter switch-ie one that screws into the radiator header on the opposite side of the inlet hose. I do have the original switch but it's not working. I assume its a sealed unit that can't be repaired-unless anyone can suggest otherwise..?
As a plan B, to fit the later push in type, one images that the rad needs to be modified?
Thanks again, Pete


How do you know it's not working? There is an adjustment screw behind a small plastic cap. Put it in a pot of boiling water to see at what temperature it opens and closes. Adjust the screw to change setting. It's a thermal mechanical device.

Re: S4 thermostatic rad fan switch

PostPosted: Fri Apr 22, 2016 12:42 pm
by archigator
If one has a push-in type otter switch, I found a Volvo gasket a few years back that makes for a tight fit...http://www.lotuselan.net/forums/elan-archive-f16/how-tamed-the-otter-t12224.html

Gary
'71 Sprint FHC
Miami, Florida

Re: S4 thermostatic rad fan switch

PostPosted: Sat Apr 23, 2016 7:13 am
by lottex
Thanks Glen,
I succesfully removed the tiny plastic cover, turned the tiny adjustment screw in and out a few turns whilst the switch was in hot water. It freed up and now works perfectly. Thanks again for the advice. I would have never found it otherwise! (And thanks to lotuselan.net !)

Re: S4 thermostatic rad fan switch

PostPosted: Sat Apr 23, 2016 10:12 am
by Certified Lotus
Glad to help Pete. The members of this community have helped me many times. It's a fantastic resource!