Dual fan with two relays - Issue

[noodl35]

I've installed my two e-fans and followed the diagram shown below. I want both fans to turn on with IGN ON. I'm using two 30A SPST relays with two inline fuses rated at 30Amps. They are single speed fans (2 wire) so it should be turning them on HIGH speed. Now I know the issue of inrush amps burning relays so that is why I used two relays, one for each fan. After using the image below, my issue is that with IGN on, both fans do not turn on. No blown fuses or anything. So my first thought was to use two different 12v switched signals as maybe wiring both fans to one would draw too much current. After wiring to two different IGN ON signals, now only the driver side fan turns on. I've followed the diagram exactly except using two switched signals. Anyone have any ideas?

http://i73.photobucket.com/albums/i235/Neil_85/180SX/E-FanSchematic.jpg

[attracted]

i would say use the ignition source from the fan thats running and change the relay and make sure all your gnds are good

[noodl35]

i would say use the ignition source from the fan thats running and change the relay and make sure all your gnds are good

I should have stated earlier but I did do that. The fan that was working, I switched it's relay for the other one (same issue). I even switched both ign on sources with no affect. I have both fan's grounded to one spot. Both relay's grounds (pin 85) are grounded to neg batt terminal.

[noodl35]

I even just took the fan pos and neg wire directly to the battery to test the motor itself and it runs perfect. So both fans do work directly to the battery but when relays are involved, they do not.

[Sir]

Check if the fan is getting voltage. I'm assuming that there is a plug for each fan.

[noodl35]

ill bust out the multimeter and check that

[noodl35]

alright, the passenger side fan on pin 87 of its relay is pulling 0 volts. The driver side fan (working fan) is pulling 12v on its 87 pin.

[copmagnet]

your diagram appears sound. The ign source that triggers the relay will barely see a load, all they do it switch the relays. So you can use the same trigger for both relays. Use the one that worked, obviously lol. Yeah, you need to break out the multimeter to diagnose this one. Make sure both relays are getting identical signals. Could be as simple as a bad solder joint internally in one fuse. I've seen it happen. If you get one working, unhook the output from it and hook it to the other fan. If that fan starts working, that helps you narrow down the search. A multimeter will answer all your questions though.

edit: just saw your new post. Check the input to pin 30 on the non-working relay. If it is NOT getting 12v, check the fuse wiring. If so, check 85 and 86 for power and ground.

[noodl35]

Went ahead and test voltage on pin 30 for both relays and they both pull 12v+.
Just for kicks again, I went ahead and put both wires on pin 86(12v switched) to the same source and again, both did not turn on with ign on. I put both wires back to separate sources and the drive side fan is the only one that turns on.

Ill check pins 85 and 86 on both relays.

[Sir]

replace the relay for pass side with another one.

And copmagnet is right. relay draws about 500ma of current from the switch source.

When you're using same source and neither one is turning on - makes me think that the relay for pass side is fucked. easy enough to test

[copmagnet]

Went ahead and test voltage on pin 30 for both relays and they both pull 12v+.
Just for kicks again, I went ahead and put both wires on pin 86(12v switched) to the same source and again, both did not turn on with ign on. I put both wires back to separate sources and the drive side fan is the only one that turns on.

Ill check pins 85 and 86 on both relays.

going from your diagram, both 85 pins should get ground. Both 86 should get 12v. Both 30 should get 12v. And both 87 should get 12v (all with the key on). You eliminated 30 as an issue. Check 85 and 86. If they both match each other, you have a bad relay. If not, well then fix the wire that doesn't match on the non-working relay. Done.

[noodl35]

checked both pins 85 (ground) and 86 (12v switched) on both relays with ign on and they are all working. I understand that the 12v ignition signal draws a very low current but when both relays are hooked into one source, both fans DO NOT turn on. When hooked in to two diff signals, only driver-side turns on, no idea why. I'm going to switch the relays back forth to test the "non-working" relay on to the working relay's harness.

[copmagnet]

your relay is bad. If they both get signal, and one doesn't work, throw it away.

[noodl35]

Haven't switched the relays yet but I may have found the problem.

With ign on, 12v switched source that goes to the working fan relay is pulling 6v.
The other 12v switched source that goes to the non working fan relay is only pulling 4.8v.

So they are not pulling 12v with ign on. Do you think this is the cause? Since one source is pulling more volts, its activating its fan relay instead of the other one?

[noodl35]

When I unhook the 86pin wires going to each 12v switched source and just test the source by itself with ign on, it pulls over 12v+ on each source.

[S-Nation S13]

http://i1138.photobucket.com/albums/n521/rontonsoups13/s13%20stuff/8dd40ee8.png
here you go i used this and mine work ones on a switch and ones on the ign source

[noodl35]

Saw that diagram but I don't want to use a switch. I would like both fans to turn on with IGN ON.

[godrifttoday]

First what ignition cable u wired ?Remember when u turn on the car with the key u start it by turning all the way to crank the car and then it goes to another position were it keeps all accessories on. U might have it wired to a momentary part of the switch.... And u don't want your fan all the time! Imagine how much longer to warm up the car! And when your in the freeway the fan essentially becomes useless after u travel a certain amount of speed... Just get a switch!!! If u do have it ground activated not by power so 86 would go to 12 volt and 85 would go to a switch then to a ground

[noodl35]

http://i1138.photobucket.com/albums/n521/rontonsoups13/s13%20stuff/8dd40ee8.png
here you go i used this and mine work ones on a switch and ones on the ign source

After looking at the diagram again, do you know if that diagram is using a SPST relay or SPDT relay. Not sure if that matters but they energize differently.

[noodl35]

First what ignition cable u wired ?Remember when u turn on the car with the key u start it by turning all the way to crank the car and then it goes to another position were it keeps all accessories on. U might have it wired to a momentary part of the switch


Forgot to tell you guys but this is a 98 s14.

12v ign on signal #1 is through the lo-fan relay using blue/orange wire.

12 ign on signal #2 is using A/C Comp relay using green/yellow wire.

I believe it's in the right position because key goes to "ON" label on ignition tumbler/cylinder. AND I hear the fuel pump prime, sending fuel to the rail.

[S-Nation S13]

im not sure, i just followed this diagram 5 years ago and my fans still work, i have one fan controlled on a switch im using the ground wire to splice my switch in "ground controlled" as for the other im using my fuel pump wire as source 12 v
im using 2 relays and 2 fuses to protect system

[noodl35]

switched relays back and forth - same issue
went and bought another relay - same issue

Looks like i'm stuck, I may just use a toggle switch afterall.

[Sir]

pull out both relays - whats the voltage to each plug at the 86 terminal? Is it still less than 12v?

If yes:
Plug in one relay - check if fan1 work
Plug in same relays into other socked - check if fan2 works

Remve relay and plug in another one and test them 1 at a time in each circuit.

[noodl35]

So I ditched the diagram I was originally using.

I had 2 spare 30A SPDT Relays laying around.

For each Fan I just made harness separately from each other.

Fan1:
-pin30 -gets fused 12v power from pos batt term
-pin87 - power wire from fan
-pin 87a - leave alone
-86- ground to neg batt term/chassis
-85 -12v switch ign on

Fan2: same as fan 1

I did not tie in any connections to each other so they run sepărate. 1 relay per fan.

Both fans turn on with ign on.

Not sure why the original diagram did not work with those 2 SPST relays tied in together. Oh well, hope this helps someone in the future.

[zerocoolalmi]

!!!!!!!!!!! use thermo switch to start fan.. :)

[noodl35]

!!!!!!!!!!! use thermo switch to start fan.. :)

I dont mind ign on fans
due to high heat summers here in oklahoma. Rb26 gets friggin hot!

[copmagnet]

Your initial diagram is 100% sound. Apparently the wire you used on 86 couldn't handle the load from the relays. I did a nearly identical setup on my car. The difference is this: pin 85 on both relays went to a universal switch that I put in my radiator. That switch was grounded. Pin 86 of both relays goes straight to 12v. 2 separate wires, 2 separate fuses. I like emergency backups. Pin 30 of each relay, also goes straight to 12v, each with their own wire and fuse. Each 87 pin gets its own fan. the switch in the radiator turns the fans on at 185 and off at 170 i believe. Can't remember exactly, been a while. The relays I used were standard blue Nissan relays robbed from a local junkyard. I have a box FULL of them. A toggle switch in my dash is hooked to ground then also tied in to pin 85 as an override to switch the fans on whenever I want. Works beautifully. The fans can run even when the car is switched off if it's still hot. If you don't like that option, pin 86 goes to a switched ignition source instead. Easy enough.

Anyway, glad you got it going!

[noodl35]

Your initial diagram is 100% sound. Apparently the wire you used on 86 couldn't handle the load from the relays. I did a nearly identical setup on my car. The difference is this: pin 85 on both relays went to a universal switch that I put in my radiator. That switch was grounded. Pin 86 of both relays goes straight to 12v. 2 separate wires, 2 separate fuses. I like emergency backups. Pin 30 of each relay, also goes straight to 12v, each with their own wire and fuse. Each 87 pin gets its own fan. the switch in the radiator turns the fans on at 185 and off at 170 i believe. Can't remember exactly, been a while. The relays I used were standard blue Nissan relays robbed from a local junkyard. I have a box FULL of them. A toggle switch in my dash is hooked to ground then also tied in to pin 85 as an override to switch the fans on whenever I want. Works beautifully. The fans can run even when the car is switched off if it's still hot. If you don't like that option, pin 86 goes to a switched ignition source instead. Easy enough.



Anyway, glad you got it going!


Nice i may have to try that sometimes

[KiLLeR2001]

What size wiring are you using and what size fuseage?

[Boost_Fiend]

I wired my fans to ign using that exact same diagram and had no problem at all. If you are sure you connected your relays correctly then I sugest you get a test light or a voltmeter to make your your getting 12v at ign. There are tons of them unter the dash, shouldn't be hard to find one.

[180sxinprogress]

whats the wiring pinout for the blue/green relays under the hood? this has been bothering me for 2 days now and i cant find shit for diagrams. :(someone help?

[noodl35]

What size wiring are you using and what size fuseage?

I was running 10 gauge wire on pins 30 and 12 gauge going to 10 gauge on pins 87. The ground 85 pins I think are 12 gauge. 86 pin (12+ign source) is fairly small. I say anywhere from 14-16.

[noodl35]

whats the wiring pinout for the blue/green relays under the hood? this has been bothering me for 2 days now and i cant find shit for diagrams. :(someone help?

Are you looking for a 12+ switched source?

[tapdeznutz]

i have a question...i am getting ready to install my e-fans too. can i just tie into the stock temp sensor wires for switching the fans on/off instead of a seperate sensor?