3 way fan switching

[Vagrant No2]

I am currently trying to fit a TonyN 1st gen cooling mod which I spotted at Sailsbury . I want to wire up the electric fan slightly different from Tony . I am reasonably good with electrics but want to run this past more qualified people we have on here .
Basically I have the fan controlled via a relay which is switched by a rad switch . I want to also control this with manual overide switch on dash with a warning light to remind me it is in overide setting , and also an off position to turn the fan off if wading (even though the vehicle is petrol).
I have worked the diagram out , but wondered if I can reduce the wirring to a min .
Is it best to control via the return earth or feed positive ?
Any suggested diagrams ?

[MattF]

Basically I have the fan controlled via a relay which is switched by a rad switch . I want to also control this with manual overide switch on dash with a warning light to remind me it is in overide setting , and also an off position to turn the fan off if wading (even though the vehicle is petrol).

The simplest solution is the manual switch and rad switch in parallel. If either one is closed, fan comes on. LED connected to manual switch for visual indication.

The cleanest method would be a changeover relay. N/C contacts connected to rad switch feed, N/O contacts to 12V feed, and relay coil activated by override switch.

Is it best to control via the return earth or feed positive ?
Any suggested diagrams ?

Either. Makes no difference. As long as you complete the circuit, it matters not.


Matt

[MattF]

Just noticed the bit about requiring a disconnect as well
Slight alteration: rad switch and manual switch in parallel via N/C
contacts of relay, N/O contacts removing 12v feed,

or:

Same as first idea I posted with an additional switch to disconnect
common contact, (30) on relay to fan.


Matt

[Gamedawn]

2 way switch with a centre off. One way feeds the thermostat contact, then the relay; the other way feeds the relay direct (plus bulb). 12V to the centre contact of switch

[Vagrant No2]

Cheers guys
Pretty much how I was going to do it . Off to ebay for a 3 way centre off switch then .Or 2 on/off switches .

[Rob]

Surely it would make more sense to have the LED light up when you've manually turned the fan off. Over cooling isn't the end of the world, over heating cos you forgot to turn the fan back on after wading is!

[Vagrant No2]

Surely it would make more sense to have the LED light up when you've manually turned the fan off. Over cooling isn't the end of the world, over heating cos you forgot to turn the fan back on after wading is!

Good point Rob . Might forget the off option now as , to be honest , I dought I will go through deep water in the old girl . To many rust holes to let water in !!

[MattF]

Good point Rob . Might forget the off option now as , to be honest , I dought I will go through deep water in the old girl . To many rust holes to let water in !!

Or two LED's. Green for manual override, red for off.
You can never have too many switches/LED's. (Just in
process of finishing an eighteen switch/LED panel for
radio slot in dash).


Matt

[Simon.O.]

.
You can never have too many switches/LED's. (Just in
process of finishing an eighteen switch/LED panel for
radio slot in dash).


Matt

Too Right!!!
I have loads of extras in mine and as for the fan it goes:
When the thermo switch in the 'stat closes
When I turn it on,
It is a part of a wider system that also has a cancellable audible alarm and a bright red light on my second temp gauge on the steering column.
I can override the system for hot starting when the fan automatically comes on with ign when hot.
BTW I can also by-pass the glowplugs for the same reason.
I want ALL of the batteries power to go to the starter motor.
Yes my dash does look a little like an aircraft cockpit.

[spans]

Too Right!!!
I have loads of extras in mine and as for the fan it goes:
When the thermo switch in the 'stat closes
When I turn it on,
It is a part of a wider system that also has a cancellable audible alarm and a bright red light on my second temp gauge on the steering column.
I can override the system for hot starting when the fan automatically comes on with ign when hot.
BTW I can also by-pass the glowplugs for the same reason.
I want ALL of the batteries power to go to the starter motor.
Yes my dash does look a little like an aircraft cockpit.

Send us a pic then

Just started to put some Led's in, and it makes it loads better !

[Simon.O.]

So ya want some piccys then??
Right here is the only way I can at the moment coz I am at home on snail pace dial-up and all my pics etc are at work on the server.

Go to this thread
http://www.hiluxsurf.co.uk/forums/sh...hlight=cockpit
Go down near the botto of the page and my last post refers to "The Grey Ghost" click that and it will shoot you to my bio page on the Aussie Surf site.
Have a look there for "My photos" and there you go
Easy as that.

[MattF]

So ya want some piccys then??

Have a look there for "My photos" and there you go
Easy as that.

Pure class. Nice one.


Matt

[Vagrant No2]

1 prob I need help with

OK , all wired in and works fine so far . I have a manual over ride position with a warning light .I even wired in a OFF light which works by wiring across the open circuit to the relay . This is fine except I can not get the OFF light off when switched to thermo switch position .
Can anyone tell me how to get this light off when in the thermo switch position , I have spent 4 hours on this 1 prob and got a headache .

[MattF]

OK , all wired in and works fine so far . I have a manual over ride position with a warning light .I even wired in a OFF light which works by wiring across the open circuit to the relay . This is fine except I can not get the OFF light off when switched to thermo switch position .
Can anyone tell me how to get this light off when in the thermo switch position , I have spent 4 hours on this 1 prob and got a headache .

Any chance of a schematic of how it is wired? Without a vague
idea, any suggestions would be pure speculation.

[Vagrant No2]

Lotus part is the answer , again

Any chance of a schematic of how it is wired? Without a vague
idea, any suggestions would be pure speculation.

Well I had another look through my switch colection and found a turn type wiper motor switch . This worked fine but was to big to fit in the space I wanted for it , but the switching worked as I wanted.
Another route around found a headlight switch from a Lotus Elan . A quick mess around and it works just right and fits in the space .

So I now have position 1 : fan controlled by thermo switch , position 2 : fan over ride thermo switch , fan on and yellow warning light on, position 3 : fan off and red warning light on .
Might fit a buzzer for position 3 aswell .
Dont really know who it works but does !!!

Lotus parts fixed my Runner twice now