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Posted

so my engine very nearly cooked yesterday i suspect the thermostats gone didnt have a gasget to hand or a thermostat so threw in a larger cooling fan and set it up on a manual switch on the dashboard.

 

quick question, is there a safe way to wire it up...

 

ive got a power lead going straight from the battery to the fan

 

then an earth lead going to a witch on the dash which is then earethed down in the drives footwell where theres a heap of earthleads bolted to a piece of sill

 

 

would it be safer to fit a relay?

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Posted
aint it easier replacing the thermostat and gasket

 

That'd be the way I'd go, and yes it's safer to do it by a relay, Don't no what switch you've used but most aren't up the large current draw a big fan can take.

Posted

Mate, get that out now.

 

A fan will use alot of current and would be fused at approx 25 amps. That switch or any switch is not designed to take that sort of current. (5/7.5 amps max)

 

As in the Volvo, the heated seats would be wired to a relay, the same as your fan.

 

I would investigate the problem first as all you have done is a quick fix, but seriously, get a relay in that circuit or worst case senario, watch your Fiesta catch fire!!!

 

If you like, I can sort you out with a diagram or instructions for you to wire up a relay! :wink:

Posted

Right the relay you will need is a 40 amp max 4 pole relay.

 

The pins will be marked 87, 30, 85, & 86. This is the normal standard for 4 pole relays.

 

You need a fused live from the battery. The fuse should be a 15/20 amp. Place the fuse as close to the battery as possible. The wire you will need is wire that will take a continuous load rating of 17 amps.

 

The directions are here:

 

Pin 85 = Ignition controlled live. Normally position 2, doesn't need to be very thick. (Low Ampage) This is from the switch you use!

 

Pin 86 = Put this pin to earth.

 

Pin 30 = The 12 volt fused live from the battery.

 

Pin 87 = Send this live to the fan using the 17 Amp wire.

 

The ignition live you will use can go into your switch. On the other pole of the switch, run this to pin 86 of your relay!

 

After you have done this, earth the other wire you have left over at the fan.

 

I would also suggest mounting the relay as near to the battery as possible. That way you will keep the main lives as short as possible.

 

Hope this helps. :wink::D:D:D

Posted

i have my realy 8) need some wires now and a fuse holder, been thinking about throwing a mk3 rad in aswell and if i can be bothered mk3 waterpump hmmmmmmmmmm

Posted
this is all well and good but, surely if its a problem with the stat(ie siezed close)none of this will help anyway.

 

i would try and rectify the problem first sam. :wink:

 

as bash says ^^^ rectify the cause of the problem first, all the fans in the world aint going to help if you have no water cirulation

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