I/C fan relay wiring

nickleman60

nickleman60

Registered User
Sometimes I wonder about myself but what's the proper wiring on a 4 pin relay for my I/C fan. My previous fan set up had no relay but now I want one in line, should have done it before. I've already tapped into the ignition wire coming out of the main fuse box to have it turn on when the key is on. I found the info below on TCCOA "how to" article. I just want it to come on when I turn the key on.

4 Pins

+12volts - 30

Ignition Coil - 85

Ground - 86

Fan - 87
 
Last edited:
If you want it to only come on when in ON/Start tap the ignition circuit, or run ground to the OEM oil pressure sending unit (will make it run only while engine is running)
 
bowez said:
If you want it to only come on when in ON/Start tap the ignition circuit,
Click to expand...

That's been done from my previous set up. I guess what I don't understand is why does 1 pin, #30, go to a 12v supply then it calls for 1 pin, #85, to go to the ignition supply (ignition wire @ main fuse box for me) ?
 
I believe the ignition wire just handles the internal switching function of the relay...just a signal for the mechanism inside the relay to switch to the constant battery 12 v circuit that will feed your fan....usually heavier gage wire and a larger load. Fuse accordingly
 
Last edited:
85 and 86 are the triggering side, with low amperage requirements. 30 and 87 are the load side, with high amperage requirements. If you ran terminal 30 off the key on 12V source, then you have to run all that power through the ignition switch, which defeats the point of running a relay. Running terminal 30 directly to battery takes the load off the switch. If you wanted, you could run direct battery power to both 30 and 85, as long as you have 86 connected to something that only sees ground with the key on, otherwise the relay will be triggered on all the time, and it will drain your battery, even if there was no fan connected to the other end.
 
I should be setting up my ic fan as well soon. I'm liking the oil switch koer option mentioned above. Any wacky gauge readings at all?
 
MadMikeyL said:
85 and 86 are the triggering side, with low amperage requirements. 30 and 87 are the load side, with high amperage requirements. If you ran terminal 30 off the key on 12V source, then you have to run all that power through the ignition switch, which defeats the point of running a relay. Running terminal 30 directly to battery takes the load off the switch. If you wanted, you could run direct battery power to both 30 and 85, as long as you have 86 connected to something that only sees ground with the key on, otherwise the relay will be triggered on all the time, and it will drain your battery, even if there was no fan connected to the other end.
Click to expand...

You are totally correct, what a brain fart morning. I went back and checked how I wired the relay to my Aeromotive A1000 fuel pump according to their instructions and it's just as you said. Thanks a lot for setting me back on track...............:eek:
 
Keith,

My IC fan (14" Spal pusher from MP) is wired to use the power leg of the main cooling fan to switch/trigger the relay for providing battery power to the IC fan. So it uses the EEC to turn the fan on and off at the same time as the main cooling fan.

David
 
David Neibert said:
Keith,

My IC fan (14" Spal pusher from MP) is wired to use the power leg of the main cooling fan to switch/trigger the relay for providing battery power to the IC fan. So it uses the EEC to turn the fan on and off at the same time as the main cooling fan.

David
Click to expand...

I want mine to run all the time that the key is on not just when the EEC kicks on the cooling fan. Where's the best place closest to the drivers side front to get a constant 12v power source ?
 
The Mega Fuse will work but if you want a cleaner install can tap any of the BK/O (black/orange) in the fuse box.
 
I have an 8" fan on my ic. It is on a 10a fuse. The ground is on a nut on my added tranny filter cooler and power leads up to the fuse and is soldered to ignition wire coming out of the main fuse box. It turns on at "start". When I want to shut it off I just pull the inline fuse. It's worked great for years.

Now a little caveat/problem/question...
I just got the car moving again after like 2.5 years down. I just noticed the plastic 10a fuse housing is getting extremely hot. I pulled the fuse and the plastic of the fuse was beginning to melt even though the fuse had not yet blown. The wires are not hot either. Could there be added resistance creating more heat from bad wiring somewhere?
 
metalman said:
Now a little caveat/problem/question...
I just got the car moving again after like 2.5 years down. I just noticed the plastic 10a fuse housing is getting extremely hot. I pulled the fuse and the plastic of the fuse was beginning to melt even though the fuse had not yet blown. The wires are not hot either. Could there be added resistance creating more heat from bad wiring somewhere?
Click to expand...

Yes - the bad wiring being the fuse holder.

Dollar to donuts it's oxidated, and that's where the resistance (and heat) is coming from.

That, or it's not really rated at 10A or so constant draw.

RwP
 
Thanks for the tip. I'll pull the fuse connectors and check 'em.

...now my fog light issue. They only come on with the brights and the flashers don't flash any more... But that's a different story all together.
 
The fog lights are controlled partly through the multi function switch - which also controls the turn signals and 4-way flashers.

I'd start there.

RwP
 
metalman said:
...now my fog light issue. They only come on with the brights and the flashers don't flash any more... But that's a different story all together.
Click to expand...

Can you pull the part number off the multi-function switch you have now? Is it blue, green or…?
 
You must log in or register to reply here.
Back
Top