I have 3 fans set up. The factory 14" fan, and additional 12 and 14" pushers fans.

They are all 3 hooked up the same way. Each on a seperate switch. All share the same ground source and all share the same power source.

The ground is switched through a relay.

I was driving doing my everyday stuff and they just stopped working. All three. So I figured that either the ground or the power was out for all of them (obviously).

To make a long story short, they all had power when the negative was disconnected. When the ground was connected, nuttin-zippo-natha-nadda-zelch--a big ZERO on the multimeter!

OK. I decided that I'd hook up a wire real quick from the battery to the fans....just a temp. fix 'til I got to a spot where I could work on it. Well, that fixed the problem...

What would cause this to happen? By the way, the power was drawn directly from the fuse box in an unused spot.

So that must have something to do with the problem, but what exactly would it be?

 

I'll shoot in the dark, but how-a-bout the relay ?

I know the horn relay which I've not research on why or how it works, but it throws 12v out on the black wire. When you ground that black wire you would think it would spark, but instead it activates the relay, and makes the horn go off. The only reason I brought that up is cause if the relay went bad I guess it could cause a short?

You could also have to much amp draw for the relay to handle? Maybe causing it to over heat.


Ron

 

You said "The ground is switched through the relay".

What do you mean by that? You have the switch activate the relay which grounds the fans?

What you should do is make the switch ground the relay, which completes the 12v lead to the fans.

I don't know if this is related to your problem (I have a feeling it is), but it's how you should wire them.

 

[QUOTE]Jza You said "The ground is switched through the relay".

What do you mean by that? You have the switch activate the relay which grounds the fans?

What you should do is make the switch ground the relay, which completes the 12v lead to the fans.

I don't know if this is related to your problem (I have a feeling it is), but it's how you should wire them.

I have switched the ground relay. In fact, what is strange is that the power source I used to get it working was directly from the battery....so I don't think it's the ground. I didn't touch that side of things.

Not to say I may have something screwed up, and I wish I did so I could figure this out.

In a little more detail...I have 3 fans, 3 switches. I had only 1 relay (a 3 prong relay, not one of the relays with the 4 prongs # 30, 86, 87 and .....can't remember the last #)....

1 switch is a 3 prong, 2 way switch. They all basically run from a ground source, through the switches to the relay and then to the fans.

And a positive runs directly to all of the fans. (somebody had rigged up the factory fan in worse fashion than this!!!! I had to cut it all out and start from scratch)

So what can I try?

 

If your have big enough wire from a switch to the fan, why would you need a relay ? I mean if you use 14ga wire you shouldn't have to.

Ron

 

because without a relay the switches melt down!

 

Well I would think you can get a good 20amp switch(s) over at NAPA that should handle it.

Ron

 

Yep. It's fried a couple of good switches, they just take longer to fry than other switches do.

This is very odd because I've wired up lots and lots and lots of things. Not just aftermarket toys either, but I've even built wiring harnesses before.....and with no trouble. But this car's electrical system is haunted!

So I drive around with everthing hooked up until it fries, fix it real quick until I can try something new....