Temp Sender & Fan Wiring

[Guest salty_monk]

Have the 76.5 stat fitted now & just wanted to ask what temp senders people use for their fans??

 

The Fiesta is quite a lot higher than this I think (planning to get the hose with 20mm threaded boss in it) am I stuck to buying a custom one? If so what temps should I go for? 90 back to 80 degrees?

 

2nd question: currently I have the fan on a switch. The switch activates the fan only when ignition is on through it's own fuse & relay. My question is can I just simply use this wiring but substitute the sender for the switch? I know I would ideally need to put an earthing lead on there eventually (as per the NW website) so that the fan cuts out when starter is activated however I have no problems with starting with the fan switched on currently (as I often do it by accident!) & I'm looking to do this quickly & without ripping out too much of the loom (don't want to get it in too many bits whilst there's a remote chance of sunny weather - leave that for the winter!!)

 

Thoughts appreciated.

 

Cheers,

 

Dan

[IanS]

My understanding is that the fan should only come on after the thermostat is fully open and before the coolant boils.. So a switch in the range of 76 to 95 should do the job.

 

Point 2 any sender that actually is a switch should easily energise a relay so go ahead and substitute or even connect in parallel so that you can force the fan on.

 

I say any sender that is actually a switch because some computer controlled systems use the temp sender and software to control the fan.

 

Ian

[Guest bloke]

do you need to use a relay with the fan?

[Guest Phil Slater]

Depending on what fan you are using they can draw substantial amounts of current so I think a relay is recommended. A wiring diagram etc. is available in the build tips section of the North West Hoodies site.

 

Phil Slater

[Guest bloke]

cheers phil, am usin the rh supplied sucker

[Guest salty_monk]

Bloke - then bin it & get a decent one... If you have the original single core rad you might want to bin that too & get a coolman or better!

[Guest bloke]

have the coolman and the sucker seems fine at the mo (not been driven yet!)

[Guest Wozzer]

Hi,

 

I took a switch from an Escort which switches at exactly 80 degrees C. It has a 22mm fine metric thread (if you need a nut to braise in). I have the low temp thermostat and it 'seems' to run OK. The fan comes on at 80 and goes off at 75/76.

 

Warren

[Guest salty_monk]

Just ordered a dual switching sender as used on the Sierra's with two fans (cossies or XR4 or something) from Premier wiring, not because I am going to use both (Jim has a dual speed fan from a Volvo that he has switched twice??) but because it will give me some choice about temp I use.

The first switch is 98 to 93 I think & the second is 87 to 83 or something like that.. will probably use the low temp one as I have the low temp stat as well, see what it runs like. If it keeps triggering on the motorway etc I'll swap the contacts over..

 

The one that cools down to 75/76 sounds a bit cool to me as the stat doesn't open till 76.5....