electric fan wiring
- Thread starter Patrick66
- Start date
MercuryMarc
Well-known member
Hi Patrick-
I have a pusher fan activated by an adjustable temp switch T'd into the rad hose, with an LED light to indicate when the fan is on- here is the schematic:
To see the set-up go here
http://mercurycomet.net/
and click on the
Radiator and Cooling - Page 1 and
Radiator and Cooling - Page 2 links in the middle of the page.
Good luck!
I have a pusher fan activated by an adjustable temp switch T'd into the rad hose, with an LED light to indicate when the fan is on- here is the schematic:
To see the set-up go here
http://mercurycomet.net/
and click on the
Radiator and Cooling - Page 1 and
Radiator and Cooling - Page 2 links in the middle of the page.
Good luck!
A
Anonymous
Guest
I just wired mine straight to the battery with a heavy duty on/off switch and a inline fuse.
Works all right for me.
Especially nice at the race track so I can let it run between rounds.
Later,
Doug
Works all right for me.
Especially nice at the race track so I can let it run between rounds.
Later,
Doug
Here are a few pre made options if you would rather not make it up yourself.
http://www.napaonline.com/MasterPages/N ... +Universal
And here is a very popular line catalog that most stores carry. The first page of this PDF catalog has the controls on them. IIRC my local fleet & farm store stocks the basic kit for around $30.
http://www.haydenauto.com/catalogs/hayd ... c-fans.pdf
http://www.napaonline.com/MasterPages/N ... +Universal
And here is a very popular line catalog that most stores carry. The first page of this PDF catalog has the controls on them. IIRC my local fleet & farm store stocks the basic kit for around $30.
http://www.haydenauto.com/catalogs/hayd ... c-fans.pdf
I have an electric fan on one of my cars to prevent the gas(if you can call it that these days) from boiling out of the carb when I shut it off. I hooked the + up to an inline fuse on the big wire on the back of the alternator and ran the ground to a mechanical timer switch like you would use for a bathroom fan. I ran the ground inside the car just incase it shorted out somehow that way all that would happen is the fan would stay on. The switch was rated for 15amps at 120vac. I didnt think it would last that long at 12vdc but it has been going for almost 10 years now. They car is not a daily driver. I did buy a relay t stat kit but never installed it. The temp probe is still stuck in the radiator and the relay I recently used on my DS2 install.
What may be confusing about Marc's drawing is the +12v part with the arrow on it connects on the relay side of the fuse. (at least I think thats what he meant)
Some (original equipment) relays have only 3 terminals.
A being the ground for the coil (in this case the thermal switch).
B being the switched + output (in this case the fan motor)
C being the + in which feeds the coil AND the contact (in this case the fuse)
More universal relays will have the same A and B terminals.
C will be the other (+) side of the coil
D will be the other side of the switch contact.
This would be handy if your control (in this case the thermal switch) didnt happen to be a ground. Same thing if you wanted to switch a ground you would need the seperate contacts. There are many many more options than that but the typical 'bosch' style auto relay tends to have 4 terminals.
Something I would add to Marc's setup is if you got a 4 terminal relay I would take the +12 for the relay coil from something like the + side of the ignition coil so it could only run when the key is on. It wont overload the system because you are only adding the load of the relay coil which is like a dash light. The power to run the fans will come from the fuse that you are hooking with larger wires fairly direct to the battery.
What may be confusing about Marc's drawing is the +12v part with the arrow on it connects on the relay side of the fuse. (at least I think thats what he meant)
Some (original equipment) relays have only 3 terminals.
A being the ground for the coil (in this case the thermal switch).
B being the switched + output (in this case the fan motor)
C being the + in which feeds the coil AND the contact (in this case the fuse)
More universal relays will have the same A and B terminals.
C will be the other (+) side of the coil
D will be the other side of the switch contact.
This would be handy if your control (in this case the thermal switch) didnt happen to be a ground. Same thing if you wanted to switch a ground you would need the seperate contacts. There are many many more options than that but the typical 'bosch' style auto relay tends to have 4 terminals.
Something I would add to Marc's setup is if you got a 4 terminal relay I would take the +12 for the relay coil from something like the + side of the ignition coil so it could only run when the key is on. It wont overload the system because you are only adding the load of the relay coil which is like a dash light. The power to run the fans will come from the fuse that you are hooking with larger wires fairly direct to the battery.
Jamie Miles
Well-known member
On my '72 Maverick, I have the fan pulling power through a relay directly from the battery. The relay is wired to a toggle switch inside the car which lights up blue when the fan is on. The toggle switch gets it's power from the Radio circuit. This way, I can turn the fan on and off while the car is running, or when I shut the car off the fan will turn off regardless of if the switch is on or off, similar to what the gentlemen above is describing. The car is a daily driver, works well. The relay is just a universal one from an auto parts store, as is the toggle switch.
Patrick66
Famous Member
im hoping to have it kick on when it hits a certain temp (about 180 maybe).
im not really familiar with electrical stuff and wiring, ive never had to do it before. so ill have to get familiar with it i guess. wiring it to the alternator was my first idea, that way it shut off when the engine did. im just not sure how to get it to kick on at a certain temp. mercury marcs setup is the closest to what i was thinking.
james, is there a way to wire it to a temp activated switch instead of a toggle switch inside the car. id rather not have to remember to turn it on and off + that way it wont drain power when its not needed. but from the battery seems to be the easiest (unless i move the battery to the trunk).
thanks for all the input.
im not really familiar with electrical stuff and wiring, ive never had to do it before. so ill have to get familiar with it i guess. wiring it to the alternator was my first idea, that way it shut off when the engine did. im just not sure how to get it to kick on at a certain temp. mercury marcs setup is the closest to what i was thinking.
james, is there a way to wire it to a temp activated switch instead of a toggle switch inside the car. id rather not have to remember to turn it on and off + that way it wont drain power when its not needed. but from the battery seems to be the easiest (unless i move the battery to the trunk).
thanks for all the input.
goto your local advance autoparts, we sell an electric fan kit that includes all the wiring to have your fan turn on a a certain temperature, I believe it runs >20 dollars, I blieve they are in 20* intervals and are adjustable to a point? Ill check it out tomorrow if you like when I go into work. But it does include all the instructions on hooking it up.
The wire on the back of the alternator I was talking about is the heavy wire that goes to the battery. This stays live all the time. I just picked this place because it was easier than adding a connection at the battery (this was a GM with the solenoid on the starter). There is no place in the car that is 'switched' that has enough power to run an electric fan so you are looking at a very heavy duty manual switch or a relay.
A relay is just a remote control switch. The theory is you locate the relay between your heavy duty power source (the battery) and the load (fan motor). That way you use the least amount of heavy wire which is cheaper, easier, lighter, and better because the longer the wire run the more other physics and physical problems you run into. You then just need a 'control' wire to run the relay. A relay coil only takes about as much power to run as a dash light so you dont need to use heavy duty wire or switches. This is also handy if multiple things need to control the same device.
Another example of a relay is the starter solenoid.
The body/mounting bracket is the ground which is one side of the coil. The S (small terminal on the battery side) goes to the key and gets a + when you turn the key to start. This then energizes a magnet that closes the switch part which then connects the big battery terminal to the other big terminal which goes to the starter motor. The little I terminal also gets connected to the battery at this time to bypass the the ballast resistor in the ignition system which gives you a bit of a boost for starting. If you go back a few years to something like a model T you had a big heavy duty switch you pressed on with your heel to spin the starter (if you even had the electric start option). Some older tractors also had a big HD pushbutton for the starter. For these types of systems they had to run the battery cables all the way to those swtiches and back to the battery and the starter. They key (if you had one) only controlled the ignition system so you could still crank the things without the key you just couldnt get them to spark.
Hope this helps you understand the how/why of a relay.
A relay is just a remote control switch. The theory is you locate the relay between your heavy duty power source (the battery) and the load (fan motor). That way you use the least amount of heavy wire which is cheaper, easier, lighter, and better because the longer the wire run the more other physics and physical problems you run into. You then just need a 'control' wire to run the relay. A relay coil only takes about as much power to run as a dash light so you dont need to use heavy duty wire or switches. This is also handy if multiple things need to control the same device.
Another example of a relay is the starter solenoid.
The body/mounting bracket is the ground which is one side of the coil. The S (small terminal on the battery side) goes to the key and gets a + when you turn the key to start. This then energizes a magnet that closes the switch part which then connects the big battery terminal to the other big terminal which goes to the starter motor. The little I terminal also gets connected to the battery at this time to bypass the the ballast resistor in the ignition system which gives you a bit of a boost for starting. If you go back a few years to something like a model T you had a big heavy duty switch you pressed on with your heel to spin the starter (if you even had the electric start option). Some older tractors also had a big HD pushbutton for the starter. For these types of systems they had to run the battery cables all the way to those swtiches and back to the battery and the starter. They key (if you had one) only controlled the ignition system so you could still crank the things without the key you just couldnt get them to spark.
Hope this helps you understand the how/why of a relay.
A
Anonymous
Guest
Patrick66":28q4h84y said:
No, its under the dash.
You have to turn on the water injection, fuel pump & electric fan then you start the car.
Later,
Doug
MercuryMarc
Well-known member
Patrick- I got my switch from the internet and it came with instructions- it is something like this:
Mine is like this one and has a probe in the rad hose, but there is a similar one with a probe that goes between the rad fins.
You can get the part from Summit at:
http://store.summitracing.com/partd...6749&N=700+400434+4294860934+115&autoview=sku
The wiring is very simple- much easier than drawing the electrical schematic!
Good luck!
Mine is like this one and has a probe in the rad hose, but there is a similar one with a probe that goes between the rad fins.
You can get the part from Summit at:
http://store.summitracing.com/partd...6749&N=700+400434+4294860934+115&autoview=sku
The wiring is very simple- much easier than drawing the electrical schematic!
Good luck!
well I took a couple of pics of what I was talking about, the switch is 26 dollars if I remember correctly and is FULLY adjustable not just the 20* I originally thought. there is another one set at 185* for 6 dollars less if you like, all instructions are included. Ill get the pics up in a minute.
A
Anonymous
Guest
patrik, if you are planning to add any other elec. acc. ie... headlights bigger alt. air cond. etc. read madelectrical.com website for relays, wiring harness, fuse blocks they are very helpful.
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