hjahmad

While driving in to work this morning, i noticed my AC fan not working. I dont remember the last time i used it since it has been fairly mild here. but this morning, its back in the low 30s and i had my temp up pretty high, but was still freezing when i go to work. usually im comfortable half way through my commute.
I tested the rest of the system. the temp changes fine and i can here all the motors adjusting the vents in all the different settings, but the fan just doesnt turn on. the fan meter on the display changes, but thats it.

the only thing i did to my car recently was complete the independent fog light mod. that was mostly complete months ago and all i did on sat was place the switch in the correct place and rewired the relay to work off the wiper motor relay so the fogs turn off when the car is off.

all that works as it should, but now the fan has stopped working. there shouldnt be a link between the two.

any suggestions as to what it could be?

ceb

I assume you checked the fuses?

mkeefe

Ceb is right, you could have simply blown a fuse. Unless you disconnected a wire or hear weird noises coming from the fan i'm guessing its simply off.

hjahmad

i didnt get a chance to check the fuses yet. i was already late for work. i might try during lunch time.
which fuse would it be?
looking at the manual, my first guess would be the no. 8 40 A fuse for the heater motor.
or would it be the sub fan motor?

Acura_Dude

hjahmad

checked the fuses. they are all fine.
i went and disconnected the fog light relay from the wiper motor fuse, since i had done that on sat, and now the fan works.
what does that wire have to do with the fan motor? that relay is on the side and verified the wire wasnt shorting anything.

ceb

You've learned something that I've been saying for years - that modern cars have multiple interrelated systems and that a modification of one system can cause a failure in another, seemingly unrelated, system.

Fortunately it was an easy fix. While I don't know enough about Acura wiring yet, I would venture a guess that the increased load on the wiper motor circuit caused the system to say "there's someth. ing wrong here" and shut down unnecessary systems - like the fan. I suspect that there were other things - probably high drain like defrosters - that weren't working either but you didn't test them.

This goes back to warning about unintended consequences. For this particular mod (illegal fog lights only) the consequences were failures of AC fan and other high draw systems.

Electrical mods on modern cars are very tricky as the self check on most cars will shut systems down when it thinks it detects a problem.

mrstak

iTrader: (1)

I was goign to direct you to Defcon's thread. he had the same issue. his was also an easy fix. I think he either turned somethign on and off or disconnected the battery or something simple.

hjahmad

Ceb,
I agree with everything you said. but it didnt make sense as to why mine was doing that at that given moment. That wire i had connected to the wiper relay was connected to the switch, which was in the off position. so there was no extra load.
im gonna experiment more with it this weekend. i have a few other ideas on how to prevent this.

mrstak, which defcon thread? independent fog thread?


What would be the proper method to add something like this? Where can i connect this circuit where it is not piggybacking off of another?
For example, the wiper relay. what is that relay connected to prevent it from turning on while the car is off?

mrstak

iTrader: (1)

Yes Defcon's independent fog light switch thread...lemme find it for you...

https://acurazine.com/forums/showpos...2&postcount=20

that's his post from his thread where he fixed the issue.

ceb

The problem is that there is often no rhyme or reason to problems with modern electrics.

Back in the day we used to be able to blame everything on Lucas electrics or Weber carbs, but back then when one electrical system failed it didn't take half the car with it.

Defcon seems to have found a way to wire the switch that works, so try that, but be sure to check all electrical systems and don't be surprised if his mod doesn't work the same for your car. Are they both the same year and model (tech or no tech) and do either have other mods?