Good ole' fans
 

Hey there peeps. I'm that guy who rarely logs in, but I am here for help. I just replaced my radiator today, got everything all setup and bleed air etc. Fans won't kick on now though, even past the 226 degree mark.

Now I never put the coolant level sensor back on the new radiator as well as when disconnecting things on the radiator I by accident unscrewed that fat nut that's on the line going into the big thing that sits in front of the radiator and it hissed out something for a few minutes before I reconnected it.

Would either one of these two things cause the fans to not kick on?

Would I be able to just hook up a manual fan switch (mine has been disconnected for some time) and then problem solved? Relays and all should be fine as the fans were working fine BEFORE this whole radiator swap.

Thank you in advance for any feedback people.

Re: Good ole' fans
 

Sounds like you might have let some refrigerant out of your a/c system with that "big nut". Wouldn't you have a large, open hole if you did not put the coolant level sensor on? Are you determining the temp by the gauge or by a scanner (scanner temp is what you need to know). A manual switch will not correct the fans not coming on by PCM command.

Re: Good ole' fans
 

The sensor port had a plastic plug screwed into it on the new radiator, so no big hole there. Yes I am only using the temp gauge though. That said, the sensor in the water pump is new so the gauge should be accurate? If I were to re-install the manual fan switch and just use that would the fans kick on with it? I don't mind the PCM not being able to kick them on, I'd just use the manual switch from here on out.

Re: Good ole' fans
 

The sensor in the water pump does not drive the gauge, the sensor in the drivers side head does. I'd suggest you scan the PCM to see what the computer thinks the temp is before you go manual.

Do you're fans go on when you put the A/C on?

Re: Good ole' fans
 

Yes, a properly connected fan switch (like the design on my site) will operate the fans if the circuitry is intact. I wouldn't recommend only manual control for a street driven car, though. That's asking for trouble.

Re: Good ole' fans
 

Adding a manual fan switch would not solve the problem. It would be equivalent to putting a band-aid on the problem. Why not fix it rather than ghetto-rig it?

Re: Good ole' fans
 

For now I am just going to install the manual switch. Financial reasons. So if I am correct, I simply splice into the blue and green (high and low speed) wires by the PCM, and then join these two new wires together then lead it to a SPST toggle switch? And run a wire from the same SPST switch to a ground source?

Re: Good ole' fans
 

No, that is not what you do. You don't join the wires and you use a DPDT switch. Read the schematic carefully.

BTW if you problem is downstream from the PCM, it is not going to work anyway.

Re: Good ole' fans
 

Have you scanned it for codes? There are codes for the two fan control circuits from the PCM.

Re: Good ole' fans
 

I think I'm over thinking this and I apologize. So I use DPDT, have one wire spliced ito the blue, run it to a port on DPDT, have a second wire spliced into the green one, and also run this to a different port on the DPDT, and finally one last wire run from yet another port on the DPDT to a ground source?

Re: Good ole' fans
 

Did you look at this, as recommended by Rob:

http://shbox.com/1/fan_sw_diagram2.jpg

Re: Good ole' fans
 

Yes I have looked at that diagram. I am not using the LED monitors so the right side I can ignore altogether correct? And as far as the other wires it goes like what I mentioned above, so basically I use a DPDT, have one wire spliced ito the blue, run it to a port on DPDT, have a second wire spliced into the green one, and also run this to a different port on the DPDT, and finally one last wire run from yet another port on the DPDT to a ground source?

EDIT: Have not scanned for codes yet, for now just wanting to install the manual switch again. Also have not tried to see if they run with a/c on

Re: Good ole' fans
 

You run the wires exactly as shown on the diagram (not just "to a port"). You also need the resistors or you will get trouble codes for the fans. You can ignore the LED part if not using them. If you don't really understand how this work, I don't recommend you do it.

Re: Good ole' fans
 

Figured I'd give y'all the update. The fans did not turn on with the a/c. I did however get the manual switch installed. All is well now. Thank you all again!