• Welcome to the new SAOCA website. Already a member? Simply click Log In/Sign Up up and to the right and use your same username and password from the old site. If you've forgotten your password, please send an email to membership@sunbeamalpine.org for assistance.

    If you're new here, click Log In/Sign Up and enter your information. We'll approve your account as quickly as possible, typically in about 24 hours. If it takes longer, you were probably caught in our spam/scam filter.

    Enjoy.

Electric Fan Switch

V_Mad

V_Mad

Donation Time
Has anyone seen one of these? Its an INTERMOTOR 50056; LUCAS SNB748; as used on MG, Rover Datsun etc.



I picked this because they are cheap and have a suitable temperature range, but I dont know how it is mounted. It looks like it doesnt have a thread like most switches, so I guess the grommet fits into a hole, then the switch pushes in, but what keeps it from popping out under pressure?
 
Nickodell

Nickodell

Donation Time
My guess is that it was designed to fit into a stepped, threaded hole in the block. The grommet and switch would go in, and a threaded collar would be screwed down onto the switch until it compressed the grommet between the ridge on the switch and the step in the hole and effected a seal.
 
64beam

64beam

Donation Time
Hi Chris,

That type of switch and grommet setup would use the pressure of the actual switch to hold it in place. I'm sure you could help it seal better with some sort of silicon type sealant. When I repaired my Alpine radiator I used a screw in type fixed thermostat switch and had a threaded boss installed in my radiator. I purchased the switch from N F auto developments who sell some other good stuff as well (switch on page 33 of their online catalogue). Here is their site:

http://www.nfauto.co.uk/

Regards, Robin.
 
V_Mad

V_Mad

Donation Time
Hi Robin
NF Auto sell an amazing range of parts dont they? I think I bought a fuse box from them about 5 years ago, but I forgot about them until now. I notice that they will even re-tap the hose unions to fit the thread of their fan switch.

I was hoping to find a low cost switch that will fit into my Tiger Intake manifold, which has a 1/2 BSP thread (I have also a 3/8 BSP adapter) but no luck so far.
 
O

ozzie alpine

Bronze Level Sponsor
I'm using something similar, but its an adjustable electronic fan controller.
On the Alpine I fitted a threaded "boss" onto the radiator, into which the controller screws. The controller is hard-wired to a relay, which is used instead of the usual fan relay. Very easily adjustable, using a small screwdriver.

On the Ginetta I used the same controller, but this time I fitted an "in-line hose fitting" version so that I could trial it in various different positions (complex plumbing!).

Got everything from www.revotec.co.uk, who were good to deal with.

Not cheap, but they have been very reliable.
 
64beam

64beam

Donation Time
Hi,

Looking at the information regarding the the whole setup, it still looks like the rubber grommet is still only held in by pressure of the switch in the grommet. The clip looks like it just stops the switch from working its way out, but I may be missing something. One question though; when installed on those cars that it was designed for, is the hole threaded where the grommet sits?

Regards, Robin.
 
V_Mad

V_Mad

Donation Time
I am thinking that the rad has a plain hole, maybe with a plain boss in it, and the grommet has a lip that fits over the inside edge, so when the switch is fitted the grommet cant be pushed out by the pressure.

I may be getting a rad recore, so that might be a good opportunity to fit a switch mounting.

I have some MGB friends who I will see on Thursday, so I may ask them if they know.
 
MikeH

MikeH

Diamond Level Sponsor
I think it is just a hole in the top of the rad. I have one as part of a V8 conversion that's not installed. I'll pop it out and take a look at it. I know on my MGB from messing with it, if I pop the clip off the edge of the switch that pressure will push it out and the coolant is hot:eek:
 
MikeH

MikeH

Diamond Level Sponsor
V_Mad said:
I am thinking that the rad has a plain hole, maybe with a plain boss in it, and the grommet has a lip that fits over the inside edge, so when the switch is fitted the grommet cant be pushed out by the pressure.

I may be getting a rad recore, so that might be a good opportunity to fit a switch mounting.

I have some MGB friends who I will see on Thursday, so I may ask them if they know.
Click to expand...


I looked at the unistalled rad and what you said appears to be true. I couldn't pull it out, but through the hose opening I could see the grommet from the inside and it looks like a lip on the inside. The switch fits the grommet very tightly. On this particular radiator the switch was moved and it looks like it is just a hole drilled in it.
 
V_Mad

V_Mad

Donation Time
I consulted a friend with an MGB and he reckons its not just a hole, there is a boss soldered into the rad. The grommet is pushed into the boss with the spring behind, then the switch is fitted. So its not as easy as I hoped (nothing ever is!).
 
You must log in or register to reply here.
Top