I just wired up my electric fan and I am running into some unusual problems. When I start the vehicle the fan comes on, however since I am using a thermostat shouldn't it turn the fan on and off at a preset temp. It seems to me like the fan is on all the time while the engine is running. (That is definitely not what I wanted)

 

Is it the JDM fan?

 

sounds like either your relay is bad or you wired it incorrectly. You apparently have 12V to the fan whenever the engine (or key?) is on.

I don't have an electric fan, but if your setup is like I am thinking, you should have 12V to the t-stat switch, and the other wire from the switch to the fan relay, this is the signal "on" wire. when the t-stat switch gets hot and closes, it sends the voltage to the relay and activates the relay. The relay should also have it's own ground and also a 12V fused wire coming into it with another output pin that lets that 12V go to the fan at the proper time (when the temp swith has activated the relay).

I guess it's also possible that your temp switch could be bad and stuck in the closed position as if it thought the vehicle was up to temp causing the fan relay to be commanded ON at all times?

Sortof hard to explain without pictures or wiring diagrams, sorry, hope this helps.

What kind of fan setup is it?

later,
chris

 

It could be setup with the ground running through the thermostatic switch instead of power. You would have the same net effect as what Superfords explained very well.

 

Thanks for the replies guys. I surely hope that it is wired incorrectly. This is the setup that I have currently :

1. 12 volt direct from battery into thermostat/relay
2. Fan negative to ground
3. Relay/ Thermostat negative to ground
4. Fan positive to in-line fuse to relay
5. Relay wire to positive AC Clutch (Power Distibution Box)
6. Relay wire to ignition on source (Power Distribution Box Relay 302)


If anybody see something wrong please let me know. Thanks for all the help. Also which direction should the fan be running ?

 

Need more info. How is if wired? Do you have the thermostat wired to positive or negitive side? What kind of thermostat is it?

 

12gage

No. 5 and 6 might be your problem. Unhook and see if the fan turns off. If it does then you need to rethink the wiring there.

Since you have hooked up the AC reference, are the heater controls on ? There are only 2 positions on the heater controls that wont run the fan..... Off and Panel.

Also it would help if you told us what type of fan you are using.
We need to know what type of thermostat setup you have. Is it adjustable for different temps? Could it be defective?

I dont think it matters what direction the fan is turning as long as the air is going the right way. ( not being a smart ***, thats just the way I look at things)
Dale

 

Hello All, sorry about the lack of info. Basically, I am using a 16" Derale Fan with and adjustable temperature thermostat.(Derale also ) Based off of what I understand after reading all the directions which at this point doesn't seem to be very much I am under the assumption that I was taping into an ignition on source to power the relay insure that the fan will not run if the key is not in the ignition on postion. (no 5) I tied into the AC clutch relay because I guess the fan should be on whenever the AC is on. I really hope I wired it wrong so I don't have to buy another thermostat. If the temp control is defective that would really suck. Thanks for all the help.

 

12gage,

I know you need this in a hurry for this so I put this together as fast as I could. It's kind of sloppy but I hope it helps.

The 12 volts can be switched or unswitched.

 

Thanks a million Chuck. (and everybody) It seems like I had everything wired correctly except I was trying to tie into the A/C clutch fuse which was always hot. I am still trying to tap into the A/C clutch relay properly. It seems like the terminals on the relay may be always hot as well. It got to the point where I couldn't tell wheter the AC overide or the thermostat was kicking in so I am letting the truck cool of a bit. Right now at least the thermostat is working independant of the A/ C relay tie in . Thanks a bunch. Any suggestions on tieing into the A/C Clutch relay ?

 

The A/C clutch relay is in the fuse box under the hood. It shows which one it is in the owners manual. You have to pull the fuse box up and snap the bottom off to see the wire. Go get one of those blue T taps that you tap off the wire without cutting it and plug a regular connector into it. The gray wire with the white stripe is a smaller guage like a 16 or smaller.

 

Thanks Chuck. All done.

 

Chuck,
We need more people like you that is always trying to help our L family out!!!

Matt

 

Hey Guys,

I had to make a change to my wiring diagram. The 2 fan motor connectors on the relay are not tied together internally. The inside one is closed applying voltage from the battery when the relay is not kicked in. When the relay kicks in the outside one closes applying voltage and the inside one opens up. I never used the inside one when I wired mine. I'm glad I went and checked that out. The wiring diagram that you see above is now the correct one.