Yet Another HKS Fan Controller Wiring Question

[speedfiend]

Alright guys I had my fan controller all wired up and working just fine years ago with my dual altima fans. I just got done with a full rebuild after six years of being down. Fan controller is on and operating and reading temp just fine but it will not kick the fans on. Only thing Ive changed in the whole setup is Im now running dual FAL fans.

I have two relays, one for each fan as well as 30amp inline fuses. I can only assume that maybe the altima fans are ground switched and the FAL's are positive switched, or vice-versa. Im no wiring guru and when it comes to relays they constantly confuse me for some reason.

Anyways I have the relays wired up as so:
Pin 85: Chassis Ground
Pin 86: Signal from HKS fan controller
Pin 87: Out to fans (connects to white wire on fans, black wire chassis ground
Pin 30: Constant 12V from fuse box (Relocated under dash)

Any in sight will be much appreciated.
Cameron

[dbeiler]

http://www.rattlebars.com/mtz/basicrelay.jpg

Your relays are wired up correctly, yes. Fans cannot be 'ground switched' or 'positive switched'. They simply require power on one wire and ground on the other wire. If you haven't touched anything else in your fan set-up during your rebuild, you may have installed non-functioning fans. Did you try hard-wiring them to a battery to see if the blades spin? FAL fans pull significantly more current than Altima fans. Did the new set-up blow a fuse or melt wiring somewhere? Sometimes people wire their FAL fans directly to their fan controller and the fan current draw destroys the fan controller. Thankfully, you've used relays in your set-up thus eliminating the possibility of overloading the fan controller. Kudos.

You need to break out the multimeter and check some terminals.
Is the fan controller outputting voltage to Pin 86 when it reaches operating temp?
Is Pin 87 outputting 12volts power to the fans when it receives trigger power on Pin 86?

[speedfiend]

Thanx for the reply man. After some further testing and checking things I have come to the conclusion that I had a grounding issue with them. I hooked them straight up to a battery and they kick right on. Im also having an issue with my alternator, ie. Im pretty sure it is taking a s*&t on me. So between the bad ground and weak voltage from a bad alternator I believe thats why my fans weren't kicking on. Would make sense seeing how much of a draw they take to run anyways.

Mods please close thread unless you feel the little bit of info posted is absolutely necessary for others.

Thanx, Cameron

[ProjectPanda13]

Great information. I'll have to visit this post when I am doing my HKS Fan Controller install. Thanks.
Latez,
-Dave