Ron U.S.M.C.

I know this should be a simple install but I'm having trouble with it any way and could use some help.
The instructions are really bad and I cant read them. I made this diagram of my fan wiring as it is now. So here it is ,
I have run a after market pusher fan in front of the radiator with a simple axillary light kit to run automatically at start up and put a in line switch under the dash so I can turn it off if I want to. I am using the main stock puller fan as backup. I need to know what wire to cut into for the new fan controller. Lets say the fan switch in the car is on so I have a close circuit through the relay now. And the fan is running. I want to put the new fan controller in that circuit . Where do I tap in ? Please don't laugh but I don't even know if the controller runs on low or high voltage. This is what I am working with =

vetteoz

iTrader: (13)

No you don't
You use two seperate circuits
Fan controller turns fan on automatically at your desired temp.
Fan switch lets you over ride controller and turn fan on at any time

Fan controller is only a switch.
You wire it the same way you have done the manual switch.
Key on , power to the controller ; then a wire to fan relay.
When thermo switch closes it will send power to relay closing it and operating fan

Ron U.S.M.C.

So I can run two wires off my low voltage side of relay. Just tap into it ?

vetteoz

iTrader: (13)

You are not running OFF relay ; you are running power TO it.

The preferred way to do it would be;
Key on power to a relay terminal.
One wire from other relay terminal to controller then to ground
Wire from input terminal on controller to dash switch then to ground
When either wire is grounded relay operates

Ron U.S.M.C.

Thank you, I really appreciate your time and effort in this matter.

Ron U.S.M.C.

OK , Can some one let me know what size fuse to run .
Thanks

Pocket

iTrader: (24)

Stock uses 20A to control the fan relays and alt. I dont see any reason to deviate. Relays take almost nothing to kick on

Pretty much the only thing you're changing from the stock relay circuit is the ground leg. Instead of thermal switch/ECM engage fcn, you're using the "Fan controller" which is a fancy product dressing up a simple potentiometer

http://www.austinthirdgen.org/mkport...an_V8_vinE.jpg

camaronewbie

And here's the instruction sheet for that controller if you can't read the printed one you have:

http://haydenauto.com/Upload/HaydenA...thermostat.pdf

Ron U.S.M.C.

What size fuse to use between the fuse box and the low voltage side of the relay?
And can you see any reason I can not put a indicator light on the dash so I know when the fan is on. Run it between the fuse box and low voltage side of the rely.Dose the light need to be rated at a certain amperage?

irock88

I would wire up the fan the way the schematics show to do it that Camaronewbie has provided

vetteoz

iTrader: (13)

WHY?
is only a switch so doesn't matter if it switches supply or ground side of relay

A smart man would get relay control power from the Ign side of main stock puller fan relay.
No need for inline fuse or extra wiring from fuse box
Then only need one wire from relay to controller ;wire then goes inside to switch

Check revised drawing above

vetteoz

iTrader: (13)

Wire light to fan ( output ) side of relay
When relay puts power to fan ;it also puts power to light
That way if the relay fails you will know.
If you wire to the control side of relay it may have power and be working but relay may not be working and sending power to the fan

Light would be on any time key is on because that wire is live ; not switched

irock88

In the schematic provided by Camaronewbie you do away with the relay one less item to break down you could still have the light if you look at the schematic, light will stay on as long as fan is running if fan stops breaking the current flow to ground... light will go out!Plus you have a manual by pass as well such as one you have shown but without the relay.
Your revised drawing isnt electrically different from your original one your just using the same leg but terminating it at a different point within that same leg

vetteoz

iTrader: (13)

Common electrical practice is not to run high current loads ( like a fan ) directly through a switch for two reasons.
You are not switching high current through the switch contacts ( which burn out ) and you have a shorter path ( less voltage drop ) from battery to in this case ;
the fan because wiring doesn't have to go through switch which in some cases may be inside car
Which is why the factory uses relays

Electrically it is exactly the same; I just redrew the wiring path so he understood what I meant .One wire instead of two

irock88

Exactly what I had said just in different terms

irock88

Switch contacts are rated for the current draw ,voltage drop your already powering your factory fan from the fuse box so how so

vetteoz

iTrader: (13)

In any case the OP already has a relay in place so my diagram reflects that

vetteoz

iTrader: (13)

You obviously need to brush up on how your car is wired
Have a look at a factory wiring diagram.





Fan power comes direct from battery through fusible link; only the relay control side is from fuse block.
As I said above ;more direct path to fan - less voltage drop

irock88

I said in` regards to your revised drawing isnt electrically different from your original one `to which you replied `electrically it is exactly the same`to which I said `exactly what I said just in different terms`
please read the replies!
And in regards to your high current I said the switches are rated for it (re burnt switch contacts)in regards to your voltage drop the factory fan is already powered from the fuse box so where does the voltage drop come from that your referring to if power is coming from the same location!

vetteoz

iTrader: (13)

You know that do you?
Refer post #18 above
I put a picture up so you can " understand " it better!

irock88

follow the fusible link in the car where does it go to (relay drivers side firewall )then from that relay where does it go and you want to talk about voltage drop on the current it draws