Fan Switch

[chocolate_o_brian 0]

hope someone can help me on this.

 

ive got a manual fan switch on my little pug. theres two (one spare) and they have both melted over time. two wires with little terminals go onto both. i wanna get another switch of better quality, but dont know what amp rating etc to get.

 

electrics are my worst nightmare, really appreciate any help on this one.

[jackherer 543]

You need to use a relay, not a bigger switch really.

[ANDYGON 6]

alot of people say use a relay, i dont see the point just use suitable switch

 

 

like this

 

i used similar in 2 different setups

Edited August 14, 2008 by ANDYGON

[DrSarty 90 1 Cars]

Relays exist for a reason; use a relay.

 

See here for a very educational & useful explanation of relays. They're easy to use, cheap, safe and not black magic. It's the professional way too.

[welshpug 1,657]

I don't see the point of a manual switch, just get the cooling system up to scratch and it'll work just fine on its own.

[DrSarty 90 1 Cars]

I don't see the point of a manual switch, just get the cooling system up to scratch and it'll work just fine on its own.

 

You're right Merion (sp?), but for those who do choose to do this, it ought to wired up safely.

[ANDYGON 6]

fair enough, you dont want voltage drop.

[evojay71 0]

I run twin fans on my road rally car and wired the second fan without a relay and on the last event it melted the switch as I forgot to switch it off,so wire it up with a relay cause you'll keep burning switches out.

[chocolate_o_brian 0]

sorted this issue out about 50%. it seems the switches were melting because of the current travelling through the wires, so a relay was a better option. the reason it has a manual switch for the twin fans is down to the previous owner, so i suspect a dodgy link somewhere (again electrics are my natural mind block so apologies on this).

 

but while trying to isntall the relay with a mate, we noticed the power line wire was extremely thin and probably dangerous to wire a relay upto it. it seemed i had two choices...

 

1. to just wire up a new switch and leave the relay out (thus melting easy to replace switches for the time being)

2. to wire the relay in, not melt the switches but then risk melting this piddly wire.

 

what i need to do is contact a member of my local car club whos a dab hand at electris, and basically start from scratch on the fan wiring. theres something a little shady about these piddly wires, and i dont wanna risk melting something other than a switch.

 

so for now i took option 1, and will eventually have some new wiring under there and a relay attached to the necessary wires.

 

it seems im using my fans too much too. i was under the impression to switch then on when the water temp hits about 2.5-3 bars on the odometer reading. it now seems apparant that i dont have to really switch them on until 4 bars on the reading (second thick line). i started doing this last night, and noticed the car seemed to cool itself down more via the radiator. i think a lot was me being worried about over heating, but not knowing the correct running temp.

[boombang 2]

Could you not just wire it up via the existing thermo switch in the rad - make it so the switch connects the two points to activate the relay which then turns fans on.

 

Minimal current running through the switch and minimal modification/adaptation of wiring.

 

Those "bodge" type connections where it just clips over the wire and cuts into it would work, just heat shrink over after or wrap in tape.

[chocolate_o_brian 0]

Could you not just wire it up via the existing thermo switch in the rad - make it so the switch connects the two points to activate the relay which then turns fans on.

 

Minimal current running through the switch and minimal modification/adaptation of wiring.

 

Those "bodge" type connections where it just clips over the wire and cuts into it would work, just heat shrink over after or wrap in tape.

 

this is it. but me and my mates limited knowledge on car electrics meant we didnt want to risk it. what you have said above means nothing to me. honestly im soo bad at electricals its untrue proper thick unfortunatley.