Hi Everyone:

Let me update everyone with my fans staying on problem. My fans constantly run until the battery is drained no matter what the temperature is, and I would hear this rapid clicking sound from the fan relays. As other members suggested, I checked the water thermosensor wiring and switch and it looks fine. I tried resetting the ECU by disconnecting the battery and pressing in the brake, I re-connected the battery and the fan relays doesn't click anymore, but the fans still stay on, now there's a rapid clicking sound coming from the UIM area. I called Pettit and I told them the situation, they told me to look for a black wire and wiggle it. So earlier I pulled out the kick panel on the passenger side and I noticed that this little black connector was grounded on the same bolt that was grounding the big black wire. I un-connected the little black wire and left the big black wire grounded and I connected the battery. There isn't any more clicking sound coming from the UIM area and the fans didn't come on immediately, but maybe 5 seconds later the fans would turn on. I waited like 20 minutes and the fans were still running. Any one else have any other suggestions?

 

i had the same problem every time i turned off the car i had to pull the fan fuse and after like 3 days it just stoped doing it

 

my fans would run at some odd times when my battery was weak. after i replaced the battery, no more clicking from the fan relays and no more fans running at odd times.

dunno if that was helpful, but its all i got for ya.

 

Did you check the relays?

 

I just replaced the battery a couple of days ago...

 

The mechanic said that the relays were fine...

 

You should put a volt-meter up to the eco lead that triggers the fans and if comes on or stays on with the car off, you might have a bad ecu. Do the fans stay on constantly or just sometimes?

 

The fans turns on once the battery is connected no matter what....

 

i dont know about u but i had same prob for about 2 months with my 325IS and as soon as i turned off and started walking away it would turn on until battery was drained, the thing is mine was aftermarket electric fan and there was a + and - things to tell it at what temperature to turn it off, so i was afraid if i crank it back my engine would over heat, took it to a garage and they put it at a spot so that when it cools the engine to a certain temperature it turns off alone.

 

Did you try leaving that "black wire" disconnected and reconnecting the battery again? If you look at Ciriani's site regarding one of the popular fan mods, they use a wire with that described location to create a timed fan mod that runs the "10-minute cooldown sequence" that was part of a tech update by Mazda. Apparently if you ground that wire it starts the sequence, but the wire has to be disconnected after a certain time, otherwise the fans will run constantly. Perhaps someone working on the car previously thought that the wire should be grounded or connected to something. That would be my only suggestion at this point. Hope it helps.

 

I believe your right about the shop guy connecting the black wire to the ground. To answer your question, I did leave that little black wire disconnected and then reconnected the battery. The fan didn't come on immediately, but probably 5 seconds after the battery was connected and the fans would turn on...I figured that okay maybe it's because the motor was trying to cool off or something so I let it run for 20 minutes and I just removed the negetive terminal again so it doesn't drain the battery. Later on that day (3 or 4 hours later) I went to try to see if the fans would turn on after I connected the battery...I figured it shouldn't because its a cooled down motor. I connected the battery and 5 seconds later the fans turned on again. Somethings obviously wrong because technically the fans shouldn't turn on. I'm totally lost on why this is happpening...

 

At this point, I believe you have an open fault somewhere in your wiring, most likely with one of your sensors dealing with engine temps, or a problem with one of your fan relays (despite what the mechanic told you). You need to check the wiring in those areas thoroughly, tracing the individual wires whenever possible. All it takes is a ground (or a drop in current) to trigger one of the relays. You are certain the battery is fully charged with an output over 12 volts cold?

And how did this problem start? Did it just happen out of the blue? Or was it after a visit to the "mechanic"?

 

I put in a new battery...so I'm positive.

This problem happend a couple days before I took it to a shop to get some maintenance and reliablity mod done (oil, trans, diff fluids changed, oil filter changed, sparkplug replaced, fuel filter replaced, themostat replaced...i'm assuming they changed the coolant in the process, downpipe, gauges, and turbo timer). I'll take your suggestion and check out the wiring. I'll do a search on the forum for the wiring diagram and take a look...if everyone has anyone has more suggestions, i'm all ears. Thank you everybody for your suggestions!

 

I put in a new battery...so I'm positive.

This problem happend a couple days before I took it to a shop to get some maintenance and reliablity mod done (oil, trans, diff fluids changed, oil filter changed, sparkplug replaced, fuel filter replaced, themostat replaced...i'm assuming they changed the coolant in the process, downpipe, gauges, and turbo timer). I'll take your suggestion and check out the wiring. I'll do a search on the forum for the wiring diagram and take a look...if everyone has anyone has more suggestions, i'm all ears. Thank you everybody for your suggestions!

 

I'm having this same problem where my fan stays on 24/7u untill it drains my batter ... when I have some time I think I'm going to wire the fans to a switch.... this problem happened when I left my car on for 10-20mins at idle...
with the daylight going away so early I dont have any light or time to check the wiring now days since it's winter