Heres why I ask, I recently burnt out 2 of my fan relays because they got wet, I bought new relays and decided I would extend the wires to the relays so i could relocate them up by the ABS unit so they wont get wet up there. Put my new relays in, everything worked great, the car had the fan mod done when I bought so I have a switch I can turn them on high speed.
Well, go for a drive, car cools perfectly, I turn the key to shut the car off and it doesnt shut off. My commander stays on but all my accessories turn. I'm confused for a minute on how Im going to shut the car off. I did figure out that if I unplug a certain one of the 3 relays my car will shut off. So Ive been driving it without that relay in at all so I can shut the car down when I turn the key off. However, no my switch doesnt work anymore and my fans turn on high as soon as I turn the key to on. They runs on high the whole time im driving and when I shut down they run for a few minutes and then shut down on their own like they should.
Any ideas? Anyone have a drawing of how the wiring to the relays should look ?
Thanks guys

 

First off I assume you've got the FD wiring diagram, if not you can download one from www.iluvmyrx7.com

I would double check the wiring to your relays because if it WAS working before you got new ones and extended the wires, then my money says you probably switched a wire somewhere.

On a side note, I did have a similar issue, though I believed that to be caused by my turbo timer and me leaving the switch grounded.

Are you leaving your switch on (ie: fans on) when your turning the car off?

 

I don't buy it. You are having some other issue, getting the relays wet won't do jack squat to them. How would you ever be able to wash under the hood?

 

Ive actually gone through quite a few relays since Ive decided to move them. Trust me you cant get those relays wet. Anyways I find it hard to believe that I screwed something up when I relocated them because I did it wire for wire and just threw in another 24" of wire. Its possible but even if how & why are the fan relays involved in any way the ECU and Ignition side of it ?

 

Ehhh, I don't buy it either. Every time I wash my car, that area gets a whole bucket of water right on top of 'em. As long as your car isn'T ON, you should be fine with hosing down everything under the hood (sans air filters).

Perhaps this is a sign of your problem. Maybe something is shorting to always keep the relay "on" causing it to "burn out" when wet.

 

The short answer would be 'no'.

One reason alone is that like any electric motor the fans have a definite service life, the more you run them the less they last.

 

Ok, the reason my relays burnt out isnt the issue. The issue is now that I know I have 3 new and working relays in, My fans stay on all the time and I cant shut my car off unless I unplug one of the relays. I looked at the wire extensions and they are wired correctly. I also read that those extensions are actually a recall mazda made and they put a little control box down by the ECU also. So if nothing has changed what could be causing my relays to not turn my fans or my car off ? Maybe bad thermoswitch ?

 

Yes it IS. You are having some kind of electrical problem, which is causing it. The underlying problem could also be the cause of your new problem. Electrical problems are a bitch and I don't envy you, but you're going to have to go through everything.

 

My new relays have been in the car for a few weeks, And I already know that the old ones burnt out because they got wet inside and rusted so the contacts wouldnt work. I didnt have them in the stock location and they got filled with water. So I guess what the problem is what is telling the relays to keep the fans on now ? My fan mod switch doesnt work anymore and is unable to shut them off. Otherwise when I shut the car down the fans will run for 2minutes and then shut as usual. And if I put the 3rd fan relay in I cant shut the car off.

 

Mate you just gotta get out there with a multimeter and measure the voltages to the relay control wires. Bust out a wiring diagram, and have a poke around to find out exactly what is happening.

There are two relay control wires - one is 12V and is switched through the ignition (see on the wiring diagram for that).

The other is GND, and is switched by the ECU/thermoswitch/AC depending upon which relay it is. This is the one we patch into, manually grounding this wire will turn on the relay PROVIDED the other control wire has 12V to it (ie: ignition on)

What I would do is get out there, and use the multimeter to measure the voltage and verify that your 12V control wire is getting 12V when the ignition is on and floating (0V) when the ignition is off.

Then use the multimeter to test continuity between the GND control wire at the relay terminal, and the engine ground. With your switch OFF, there should be an open circuit (ie no continuity) and with your switch ON there should be a closed circuit.

 

Wait you mean you can't shut the CAR off or the FANS off?

I thought you meant fans.

 

When I have the third relay in place I cant shut the car off, all the accessories shut off when I turn the key off but the ecu & car stays running. If I pull the relay out it doesnt seem to change anything except then I can shut the car off when I turn the key off. But the fans stay on high constantly when the car is on, If I pull another a 2nd relay out while its running the fans drop to medium and if I pull all 3 no fans at all... Im kinda stuck, im going to basically ohm every relay I can find and I guess follow all the wires from the relays around and see what else there is to see. For the last few days Ive been driving it without the one relay so I can shut the car off and nothing else seems to be weird besides the fans staying on...

 

Have you only got 3 fan relays? There are supposed to be 4. Two are controlled by the same ECU output.

It sounds like your saying there is one PARTICULAR relay that will allow you to shut the car down when you remove it. Which relay is it (by that I mean what stock part of the car is it that operates that relay)

What you have described (fan speed decreasing as relays removed one by one) is what I would expect to happen if all the relays were on and the fans were on high to start with.

 

You may have shorted out some of the relay lines. I had this same problem before where the fans wouldnt turnoff ever after I shut down the car.

BTW, I think its perfectly acceptable to run your fans all the time. I'd rather have the fan fail and replace it than risk overheating my motor.

 

Yeah, but when your fan(s) fails, how will you find out? Most likely you'll notice the temperatures rising, and that's flirting with danger.

 

Not really, the highest I've seen it without my fans on and the car completely warm is maybe 95C. I think you would have to have a problem with more than the fans to overheat. In addition, I run the fans for a bit when I shut off the car, so it would be very noticable if the fans aren't running.

I wouldnt be worried about temps unless I see the temps break into the 100s. When my thermostat gave out, I saw constant temps of 105-110 Having a thermostat give out is a lot more worrisome than the fans.

 

I was trying to think of how you would tell that the fans were dead, and didn't even think about running them after shutdown. I do that to, so yeah it would be very obvious, good point

 

at what point did the relays get wet? was this before or after you added the extra lengths of wire? and how did you wrap this wire? id start there. -heath

 

The relays got wet before I extended the wires. I extended the wires and put new relays in at the same time. I just put the finished wires inside of some of that flexible plastic tubing and taped it shut with electrical tape. I think im going to take the extension wire out so it will be stock again and see if things go back to normal. I did buy some heavier gauge wire when I made them longer but the guy where I bought the wire said that would matter, he said current will pass through it either way... So I dont know if maybe that could be it, the heavier wire adds more resistance ?

 

Thicker (heavier wire) is less resistance. You'll notice in the stock wiring harness that two wires per relay are quite thin, two are a fair bit thicker. The thin wires are what turn the relay on/off and do not carry much current. The thicker wires form part of the fan motor circuit and therefore carry greater current (not sure exactly how much)

For the two thin wires, it doesn't really matter what gauge you use because those wires carry bugger all current. For the thicker wires, you would want to use wire of at least a similar thickness or even thicker.

So have you only got 3 relays? And if so how come?

 

i run mine all the time. mainly bc they wont kick on automatically anymore....

 

 

Did your fd already go through getting the "problem areas" fixed? If so, you should have five relays behind your passenger head light. If you haven't already done so, replace all five relays and eliminate the possibility that the other two that weren't replaced are bad.

 

I have 4 relays but the ones that are giving me troubles are the 3 that are the same as each other. The other one (The bigger main fan relay) seems to be fine. I guess the fans being on all the time isnt what concerns me the most. Basically why is that one relay when I put it back in and turn my key to on, then turn it to off, my powerfc stays on & the only way to shut everything off is to remove that relay. However, if the car is totally off and that relay is out, I can put that relay in with out it turning anything on, but as soon as I turn my key to on it triggers that relay and wont allow me to shut my car off. Im so confused.

 

Good OK so you've got 4 relays.

Do you know which is which (I mean do you know what controls each one?)

If you don't I would get the wiring diagram and go out there and figure out (from the wire colours) which relay is which. It would be a big help to know which relay is causing your engine to keep running. Is it one of the ECU relays? Is it the relay controlled by the AC circuit, or the relay controlled by the thermoswitch? Once you know put a sticker on each so you won't forget (I wish I had done that!)

If you haven't tested the relays yet, pull them and test each one individually for correct operation.