manual fan switch install

96redhotgt · 03-25-2005

can anyone direct me to a thread that talks about wiring in a manual fan switch for a '96 GT?

96redhotgt · 03-26-2005

never mind, I found the tech article.

96redhotgt · 04-07-2005

Except for having to stand on my head, that was an easy mod. The hardest part was having to move the 3 wire bundles out of the way to get to the wire bundle for the PCM. Now that I know that the wire for pin 46 is the light green with a purple stripe, I would suggest looking for that wire in the bundle instead of moving all of the other bundles out of the way. You could probably trace it to the connector just to be sure. (second row, the last one is 52) It works great by the way.

AZ Stang 97 · 04-07-2005

Just curious, why did you want a manual fan switch?

96redhotgt · 04-07-2005

Because whenever I drive for awhile, then stop to park, the engine heats up to the point(221 degrees) where the fan comes on. I don't like to shut off the engine when it is at max temp so I have had to wait for it to cool down before shutting off the engine. That takes time so I now I can turn the fan on just before parking to cool the engine down and not have to wait. It is also very helpfull when at the drag strip for keeping the engine cool before the launch.

BT1993 · 05-05-2008

Quote:

Originally Posted by 96redhotgt

never mind, I found the tech article.

Where is the tech article? Cant seem locate it in search.

mustank · 05-05-2008

I just wired mine back to come on thermostatically. I twice overheated because I forgot to turn the fan on. I guess I'm too absentminded for a switch. lol

96redhotgt · 05-08-2008

You can find the article on the fan switch wiring under "Articles" and then cooling and a/c systems. It's right at the top of the page.

yfz162 · 04-11-2009

I realize this is an extremely old thread, but maybe someone can help me out here. My cobra has this fan switch mod done and i can't get the fan to come on after reversing the mod. I unhooked the wiring and the only way the fan will run is if the AC is on...... Do i need to have the original fan settings reset from a tuner or dealer? The fan never worked on it's own with the switch wired in anyway unless the AC was running. The article makes it sound like the fan should work as normal with the fan switch mod done, but mine wouldn't. Any ideas?

96redhotgt · 04-11-2009

yfz162, the fan should run normally after that mod is done, if it was done according to the instructions I used. The only odd thing I noticed is that if I turn the fan on myself but the temp becomes high enough for the temp switch to close before the fan cools the radiator, the fan will slow down a bit, so then I turn the switch off because I don't really know if it is ok for both switches to turn the fan on at the same time or if that is what is actually happening. Otherwise, it works all the time with a/c and on low when the temp hits 121 degrees. Your temp switch may be faulty. It is on the intake manifold on mine, I'm not sure about Cobras. There are two on mine, one for the guage and one to turn on the fan.

yfz162 · 04-12-2009

Ok, i just want to make sure the mod was done correctly in the first place as it was done by the previous owner..... My car has a jumper/tap wire goin to a light green wire with a purple stripe behind the pass. kick panel and another wire grounded to the body. Both of those wires run to a toggle switch on my shifter bezel. Does this sound correct? If so i will get a new temp sensor and see if that does the trick. I am only assuming the fan doesn't work. I let my car idle until the factory temp. gauge was up around the M or A before taking it out on a drive to cool it. I understand that is "normal", but seems like the fan should kick on well before the gauge reaches that high right??? Can you think of anything else i should check?? Thanks for your help redhotgt!

96redhotgt · 04-13-2009

The fan should come on when the engine is at 121 degrees on a GT. I don't know about a Cobra. If you could measure the engine's temp while running as in putting a thermometer in the opening of a radiator (can't do it on a mod mustang), you could find out if the temp sensor should be telling the relay module to turn on the fan. I replaced that module before the sensor with no help and was out about $180 or so, I think. It is really difficult to access, in the right wheel well. On mine it comes on with the needle at about the r/h side of the M. I think it is a different relay for normal cooling so it could work with a/c and not during normal running temp.

96redhotgt · 04-13-2009

YFZ162, I mistakenly typed 121 degrees when it should have been 221 degrees. Big difference. By the way, even the Haynes manual has quite a bit of info on this stuff. It gives the resistance values for the temp sensor(58,750 to 40,500 ohms at 50 to 65 degrees F) (3600 to 1840 ohms at 180 to 220 degrees). You can take it out and boil it and read the resistance that way. I find that much easier. You need to get a thermometer that will read over 220, sold at any auto parts or hardware store. Same kind used for air conditioning work on houses, etc, and an ohmeter, of course. The fan does use a diferent relay for low speed, high speed, and a/c on. Also, I noticed that the fan runs on high when using the manual switch, so I guess that would be the relay used when the a/c is on and temp of engine is high. Good luck!