Help wiring electric fans

[DSMboostin15]

Alright, I just installed my new Punishment radiator and wired up the fans by cutting the stock fan wiring and splicing the new fans into the pigtail. The problem is that when I let it go through a complete heat cycle, the fans don't kick on like they are supposed to. I've looked through the FSM and doesn't really tell me which wire is the positive and which one is the ground. The way I have it wired is that the BLACK wire from the pigtail is wired to the RED wires from the fans, assuming that it is the positive wire, and the BLUE wire from the pigtail to the BLUE wires from the fans, assuming that they are the ground wires. Now another question is that do I have to have the connector from the A/C fan side connected and wired to complete the circuit in order to make the fans turn on or can I just leave it disconnected at the connector, theoretically eliminating the A/C condenser fan circuit? Sorry for this being a long post, but I prefer to be in depth when it comes to a problem diagnosis. Thanks for any advice.

Ok, I've tested the fans by connecting them directly to the battery and they work. And I've switched the wires from the stock harness (BLUE,BLACK) thinking I had the wires reversed, but that didn't work either. I've let the engine heat up to 230* and the fans still don't kick on. I'm thinking that I may have blown the fan relay, but I'm not quite sure on that. If anyone can give any insight as to how this system works and what to look for, it would be greatly appreciated. Thanks.

 

[xveganxcowboyx]

Put a volt meter to the fan wiring and figure out if it's got power and which is positive. I unfortunately can't remember color coding on that right now. Of course the car has to be warm for this to work.

You can also push the AC button and should have power to the secondary fan wiring and could run off that.

 

[BoostedTalonTS]

As far as 1Gs are concerned,
IF you unplugged the AC fan, you will need to reconnect the resistor in order to complete the entire fan ciruit... That resistor is what is responsible for the Hi/Low fan speeds in a 1G. -If anything, just cut it out all together and splice the resistor wires (car side) together. This gives you a single, full output fan speed on both fans, provided that you wired the aftermarket fans back to the OEM fan wiring.

Secondly,
Be sure to observe the fan polarity... I used a Makita battery to test the fan direction on both the OEM & aftermarket fans..... MAKE SURE that they are wired up as pullers and have the reversible fans blades switched accordingly.

EDIT:
Another thing to check is that you also are plugging in the lower thermosister that is in the lower tank of the radiator... With this unplugged, your fans will never turn on under normal heat cycling conditions either.

By having the AC turned ON, with the ignition on, you will "manually" activate the fans. -Use this as a final test.

Good Luck

 

[DSMboostin15]

I didn't think to check the power when the engine is running. As for running off the A/C circuit, I not really a fan of running things like these off of switches.

Well I checked the power to where the fan would be and there is no power. So could this be caused by a blown fuse/relay, or could it be caused by the coolant temp sensor (Thermosensor - FSM) being dead? As a side note, according to the FSM, the sensor that is located on the thermostat housing next to the filler neck - the engine coolant temperature switch (Air conditioner), does that have anything to do with turning the main fan on or does that just deal with turning the secondary fan on when the temp gets to a critical level? I bring this up because mine broke in half and I replaced it with one from the junkyard, but that one is cracked as well, just not to the same degree. I also have one from a Sonata. It is the same thread pitch, length, and connection but I think that it might have a different resistance. Sorry for a long post, but I'm trying to analyze everything that can make the system fail.

 

[BoostedTalonTS]

What about the resistor on the OEM AC fan?

 

[DSMboostin15]

I'm not sure that I follow.

 

[BoostedTalonTS]

look at your factory AC fan... see that large square metal heatshield that's bolted to it? -Behind that heatshield is a resistor... It NEEDS to be hooked up to 2 of the 4 wires going to the AC Fan or else the whole system will not work.

Here's a pic...

 

[DSMboostin15]

Well that would make sense. But I thought that the resistor only controlled the A/C fan. I don't have the stock A/C fans on the radiator anymore since I replaced the entire radiator and added a pair of slim lines. So if this is the case, how do you recommend I wire it up where both fans come one with the Thermosensor, not just the passenger fan?

 

[BoostedTalonTS]

Well that would make sense. But I thought that the resistor only controlled the A/C fan. I don't have the stock A/C fans on the radiator anymore since I replaced the entire radiator and added a pair of slim lines. So if this is the case, how do you recommend I wire it up where both fans come one with the Thermosensor, not just the passenger fan?

You might want to re-read my earlier post (POST #4)... That resistor is not JUST for the AC fan... It's responsibly for BOTH fans. -Our 1Gs have a Hi/Low fan speed ON BOTH FANS from the factory... Without that resistor in place you have literally opened the circuit right in the middle of the factory wiring and nothing works.

Correct this by locating the two wires that went to the resistor... Either reconnect the resistor << OR >> Connect them together. BE CAREFUL THAT YOU ONLY CONNECT THE TWO RESISTOR WIRES TOGETHER... The OTHER 2 wires are for the fan itself.

Hopefully you didn't cut any of the car's wiring yet... SAVE the plugs and cut them FROM the factory fans themselves. -This will make it easier in identifying the 2 wires that are specific for the resistor... Either way, leave the resistor in it's place or cut it out and connect each of the wires together. -Your choice... Hi/Low fan speed or FULL speed when needed, provided that you wired your new fans to the factory fan wires.

 

[DSMboostin15]

So far the only cutting was the main fan side - the thermosensor and fan motor harness. My thinking was that this harness was what controlled the main fan. I used this mentality when I wired up the fans. The way I originally wanted to do this was to wire both fans in parallel so they would both turn on when triggered, not just one then the other when the temp went too high. So theoretically I was correct when I originally wired in the fans - minus the fact that I had the resistor disconnected entirely.

For making the connection, let me see if this is right - reconnecting the resistor will close the circuit and make the fans run when at temperature, but at variable speed. If eliminating the resistor, this will cause the fans to be on full when triggered. Now the question is, if I wire the fans in parallel, the way I had it, will this still work without creating excessive current draw on the circuit and blowing something?

 

[BoostedTalonTS]

Either way...
I'd be much easier to wire up one fan from each side as it's less load on one side and you don't have to worry about running wires across the face of the radiator... After all, it IS one of the hottest areas in our cars with ambient heat radiating from the turbo & the hot air expelled from the radiator itself. -IMO, I'd eliminate the resistor and wire each fan to each side... They will then both turn on simultaneously and operate at full speed.

 

[DSMboostin15]

Here is a pic of how I ran the wiring from the second fan. The wire runs along the shroud lines and is barely visible for a clean look. From where the wires meet, I soldered them together and ran 2 wires to connect to the stock harness, which isn't visible in this pic.

 

[BoostedTalonTS]

Missing heat shields too? -YIKES!! Do you think that those wires will be able to withstand those high temps? WTF Good luck with that...


-I take it that you finally figured out what to do with the resistor.

 

[DSMboostin15]

Well the heat shield had to go, as it was rusted completely through and wouldn't stay on. I'm still in the process of looking for one that is in good shape.

As far as the resistor goes, there is nothing about wiring slim fans with the stock wiring for a 1g. Everything I've found for wiring was either running a separate line with fuse and relay or using the stock wiring on a 2g and as I know now, the wiring is completely different on a 2g. So I'm in the process of writing a "how to" on how to do this on a 1g. Thanks for all the help.

Update: The fans are now wired correctly. I eliminated the resistor and soldered the 2 wires to it together. The fans come one when the A/C button is pressed, but don't come on when at temperature. This leads me to believe that the coolant temp sensor at the bottom of the radiator is gone and needs to be replaced. I jumped the connector and the fans turn on. I guess I'll go and buy a new sensor.

Also, what exactly does this plug do? The FSM says that it is the "Engine coolant temperature switch". You can't see it in the pic but the plastic part of the sensor is broken and I replaced it with one from the junkyard, but it is cracked as well. I happen to have one from a Sonata that is the same length, thread, connection as the stock one. Do you think this will work?

 

[Icarus]

I recently did a fan install so I have an idea of what you're trying to do. I have the A/C connector unplugged right now. I went a little overboard trying to make things stay cool, 4x10" fans. My first thought was that you blew the 30A fusible link located on the + terminal. I am running a relay for the 4 fans but my load is pretty close to 30A, probably not so for the 2 fan setup. If you checked that and it's good then I would agree about the radiator switch. I know it sounds stupid, but I would check the connector before buying anything. It could be loose or corroded considering the location. I hope the fans work for you. I am still not happy with my setup.

 

[DSMboostin15]

I was thinking the same thing. The connector to the sensor has some corrosion on the terminals, but I still think the problem lies in the sensor itself. I do believe that it is the original sensor since I had the original radiator, which are 18 yrs. old. And I did notice that even before I installed the new radiator/fans that I was getting overheating issues at idle. Besides, it's only an $30 sensor and it will eliminate that part from the equation.

 

[DSMboostin15]

Well it turns out that the problem lied with the radiator fan switch. I thought that this was the problem as when I jumped the connector with a piece of wire, the fans kicked on. So I bought a new sensor and that did the trick. Thanks for the help BoostedTalonTS.