well as soon as i turn the key on the on position the fan starts and when i start the engine it always stays running. Someone told me before the ecm is in some kind of mode how do i find out if it is and how do i fix this (it throws no codes) also could the last owner maybe rigged it for it to always run if this is the case what parts will i need to have it operate normally. It is the dual fan btw.

 

When i bought my car mine were wired to run all the time which isnt really a bad thing if youre in a hot climate like mine most of the year.Ive heard its an old hot rod trick to get your ecm to put more fuel in the mixture due to the cooler more densly oxygenated air not sure if it works but i just left mine that way.BUT,NOW ITS SUMMER AND THE FANS I HAD TO REPLACE LAST YEAR,one of them isnt working again so id say it eats them up quicker and wears them out.SINCE MINE IS NOT A DAILY DRIVER I'LL FIX MINE AND LEAVE THEM WIRED UP FOR NOW SINCE I need my car running cool as possible for this 100 degree weather we are already having in MS.

 

I have heard that you can pull the wire that connects to the fan switch and ground it and a fan will run when the key is on. The fan switch is screwed into the head right between the #6 and #8 spark plugs located on the passengers side.

 

When I bought my IROC the fan ran all the time until I noticed the coolant temp sensor plug was loose, the locking tab was broke off. Fixed that and the fan worked normally. Something to look for maybe.

 

Which fan is coming on? The primary, the secondary or both? I had a problem with my secondary coming on all the time and it turned out to be the fan switch & the connector. The connector had fallen apart from age and fan switch was bad also. For the secondary also check the A/C fan switch. For the primary check the CTS. Most of the problems with the fan relays & fuses normally cause the fans not to come on, but worth a look too. Hope this helps.

 

both fans come on there too sensors by my a/c that are disconnected and have no idea were they go.

 

It looks like the ac pressure switch has a gray and a black w/white stripe wires connected to it. It should plug into the sensor that sits on top of the aluminum tube by the passenger strut tower area.

 

The A/C compressor has a pressure switch that plugs into the back of it. While the A/C fan pressure switch, as someone else posted, is attached to the aluminum tubing that runs from along the wheel well and bends down low and connects to the condesor up front.

 

the fan switch is located under exuast manifold passenger side. its a switch to ground which means that as the temp gets up to 230 something it opens up ground and kicks fan relay on. when this switch fails it becomes a constant ground which means instead of not running fan at all it will run it all of the time.

 

i dont know the reasoning behind this, but i know my friends mustang 5.0 does the same thing...even when the car is turned off, the fan randomly intermitenly turns on. dont know what to tell yas...sorry dude.

 

today i was messing with it and checked the fan switch the last owner ripped the wire out of the part that screws into the block and grounded the water on the strut tower nuts so the fan would always run so when i get a new fan switch it should work fine. thanks for all the suggestions