Fan Relays
 

Anyone know which one of the four fan relays would cause the fans to stay running after the ignition is switched off? thanks

Do they run untill you do something to disconnect them OR do they run for about 10 minutes and shut off .The ten minute thing is built in with later models .

hey David - I haven't timed it, but they never stayed running with the ignition switch on before

To turn the fans on, it's a combination of at least 2 relays... I can look up the diagrams again if you need it because I can't remember the setup off the top of my head...

what have you changed recently that could contribute to the new behavior?

not to hijack.

But my FD - suddenly fan were not shutting off. I had to pull the fuse to get them to stop. Now fans won't run once temp is reached. But I can turn the car off, then on and the fan come to life. I am assuming it the fan relays. I plan on just replacing all of them.

YZF - rx7.com may be able to help you and order the correct relay at the same time.

The car was down for about six months earlier this year for new coolant seals, and I think it was that, plus the fact that it's an 18 year old car - I put some dielectric grease on the relays, combined with just driving the car more frequently now, the problem seems to occur less often, but I'm sure they're still on the way out

I wouldn't mind looking at the diagrams if you can post, thanks

Would this help?
----> http://www.fd3s.net/fan_circuit.html

Yes it does, thanks

There is also a recall control module added to the fd's located next to the ecu. It's a little black box that allows the fans to run if the car is turned off and the temp is at a certain range. I have had to replace said box to get this system to work again, before I removed the factory fans and relays from the car when I built a custom cooling system.

I think I've seen this black box, what happens if you just disconnect it?

If you remove the box and the adapter wireing harness it will go back to the way it came from the factory . It is just an unplug and replug the harness

Fans run for 10 minutes after the ignition is off, right?

Something like that .
I have had that system removed from my car for years and I never put a clock on it when I replaced the control box.
sorry

My biggest concern is draining the battery running the fans that long...

If the battery is of good condition 10 min or so fans running to remove heat should not be a problem. A lot of new cars now days have this kind of system and if I remember when the control box turns the fans off the system turns off (not sure on that but i think that's how it works.

Just to confirm...running the wire lead to ground will cause the fans to run 10 minutes after the ignition is turned off but only if a threshold temperature is reached on the engine (can't recall now exactly what it is). So you don't have to worry about the fans running EVERY time you start your car.

As mentioned, if your battery is good there should be no problem and it does help a bit with underhood temps in the summer. Before moving to a PFC I used it for several years (through a switch so I could disable in cooler times) with no issues.

Im putting in new fans but theres two wires on the new bl and blue 4 on each old help i know black is ground and blue is hot on the new fans

its a 93 fd

on my 93, there was an extra harness inline with the relays that pretty much just shorted batt supply and ignition supply, so that fans would run with ignition turned off. if you remove this harness and plug straight into the relays, they wont turn on without the key turned

mybadrx7, BLK and BLU/ORG are ground, YEL/WHT and RED/YEL and WHT are 12V to fan