wiring up thermo fan spdt relay

Hey Guys,

I have been having issues wiring this thermo fan up.

The LED light on the Fuse is always on when the ignition is off.
The LED light goes off when the car is turned on.
The LED comes on when the thermo switch hits its open ground (90degrees)

The fan does not run...the light just turns on....my radiator is being cooled down by running the heater on full lol, i need help please.

This is a diagram ive made.....this is how im running it at the moment.



Thanks alot
Michael

Where is the LED connected?   According to your diagram, the fan should be running anytime the ignition switch is off.  And any time the temp is below 90 degrees.  If your fan is not coming on with the ignition off, you have a bad connection somewhere or a faulty fan, relay or fuse.

the LED is connect to the inline Fuse...its ment to come on when the Fuse is blown....but its not blown.

How should I wire this up so the fan comes on at 90degrees and only turns on when the ignition is on?....I dont want the fan to run while the car is off as the battery will drain.

And also which wire should I tap into if I want to run a manual switch inside the car so I can run it all the time at the racetrack.

Thanks heaps.

If it is an AGU type fuse, replace it.   The switch states normally closed, does it open somewhere between 85 and 90C?

Nah its not an AGU type fuse.

Its the same as this:



but mine has an LED light on the bottom...usually lights up when the fuse is blown, but its not.

Yeah its normally close ground.

The switch opens at 90degrees and the switch closes at 85degrees



I will double check the fuse isn't blown...was hard to tell...very dark at night when i checked.

My diagram should work!

Your diagram = dead battery in the morning.

thanks alot mate :)

fuse was blown too....tried to put a new one
in but blew straight away, the fan tried to run while the car was off with my diagram, i will test out your relay diagram and see how it goes.

thanks :D

A large cooling fan requires a lot of current to start up. Yeah check my diagram out and let me know if it works.

ok no problem :),

Also in your diagram....I want to add in a manual switch inside the cabin of the car.
What would I need to do?

thanks
michael

its working fine now :D

thanks alot for that!

would you know the above question though?

thanks

I will post a picture tonight.  It requires (2) 1N4001 diodes available at Radio Shack.  Attach both diodes to the point that now says 12V Ignition, with the banded end of the diode nearest the relays.  Non Banded end of one goes to 12V ignition.  Non Banded end of the other diode goes to your switch.  Other terminal of the switch goes to Acc wire or to the battery.  Place a 3 amp fuse at the point of connection.   If you run it to Acc, it will only come on with key in acc position.  If you run it to the battery, it can come on anytime the switch is turned on.

hey guys,

Im back! I recently just purchased a new thermo switch which turns the fan on a slightly lower temp.

Its the same connection on the switch except its a Normally Open Ground instead.

Im thinking all I have to do to my current wiring is put the Positive wiring from the Fan to 87 instead of 87a.

Is this correct.
thanks in advance.

Yes you will need to use 87 instead of 87A on the top relay.  However you will lose the ability of the switch unless the temp is above the threashhold of the switch. 

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Let's Go Brandon Brown. Congratulations on your first Xfinity Series Win. LGBFJB

No worries,

I have changed it over to 87 and drove the car to around the 91 degree mark and the fan did not come on....I have the same wiring as before but I never connected the switch up as I didnt think it was nessesory.

Any tips? and also with this setup could i run it like this?

if you are sure you have 12 volts on the ignition wire and on 30, there is a problem with the temp sensor. or the relay.

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Let's Go Brandon Brown. Congratulations on your first Xfinity Series Win. LGBFJB

no worries i will have a look...

can I run the relay with the above diagram or will it cause any issues?

cheers

evo180sx wrote:

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no worries i will have a look...

can I run the relay with the above diagram or will it cause any issues?

cheers

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also the Temp sensor is brand new...and the relays were working yesterday...if there was a problem with the relays it wouldnt be able to work with the old diagram?

There will be no issues with your diagram.  Well, no issues beside your current problem.

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Let's Go Brandon Brown. Congratulations on your first Xfinity Series Win. LGBFJB

All wiring is fine, test 2 relays and still not working.

I pulled the wire out from the switch and put it to a ground and the fan worked....so the temp switch is faulty! :(

Is it possible that the 85 is the point in which the switch returns to normal after it is tripped by the heat.  Have you thought about boiling the switch and seeing if it maybe takes around 95 degrees to activate?

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Let's Go Brandon Brown. Congratulations on your first Xfinity Series Win. LGBFJB

yeah trip heat is 85deg and it returns to normal at 80deg.

I just hooked up my old switch (naturally close ground)
and now thats not working....im really confused now!

I hooked the old one up exactly like the diagram has on here with 2 relays etc also.

All I can think of is when it reaches the trip tempreture its not grounding for some reason...but its screwed into the radiator!

any ideas lol

thanks for the help :)