[454headache]

So I just spent a few hours wiring up a Taurus fan, making everything nice and tidy. Hopped into the truck, flipped the switch, only to find it does nothing. The fan works in both high and low, both relays and the fan are wired right, so the only thing that i can think of is the s three way switch. Here's the switch http://www.napaonline.com/Search/Det...62_0006481197#
The middle I wired to ground, the bottom the low fan relay and top to high fan relay. Is this right?

Here's how I wired the fan:
http://www.jeepforum.com/forum/f13/f...l-pics-233676/

[75gmck25]

He has the relays grounded in the engine compartment, and switches the 12 volt power to activate the relays.

If you wired it exactly like his article, you need to wire the center post on the switch to a 12 volt source that is only on when the ignition switch is on.

When you apply 12 volts to one of the terminals by flipping the switch with the ignition on, it will turn the fan on. Just make sure you leave the switch in the low position, or you won't have any fan running at all.

Bruce

[Rickracer]

Your high relay will need 12V+ to activate it, the low relay may need positive or negative depending on how you wired it. I designed a circuit for those fans that works pretty well, and is all automatic. You can find it here: http://www.crankshaftcoalition.com/w...ontrol_Diagram ,

[75gmck25]

The wiring diagram you posted is quite a bit more comprehensive than what the Jeep guy did in the Jeep Forum article. He also did not post a wiring diagram.

In the Jeep article he said that he activates each fan with a single pole, dual throw, on-off-on switch, with the center post connected to 12 volts. Based on that, he must use 12 volts to activate both the high and low speed relays.

Bruce

[454headache]

Switched the center to the battery positive just to check things out and nothing, well alright now I get a click from the low fan relay at least. But nothing from the hi amp relay at all, as always.

The 30 amp is wired as follows:
Low Speed + from fan connected to 87
Switch connected to 86
Ground to 85
Battery positive to 30

[75gmck25]

Do you have the fan grounded to the frame? And is the high amp relay grounded to the frame, like it is in the article?

If you are getting a click from the low speed relay, it sounds like its activating. That would mean that when it clicks it is connecting the 12 volts on terminal 30 to terminal 87, and to the fan + side. You could just use a multimeter to verify that you are getting 12 volts on terminal 87 when you activate the switch.

Bruce

[454headache]

The fan and high amp are grounded the same way as the article. I can activate the high by shorting the M to B terminals. So the fan does work. The low speed also work when I connect the wire from the fan to the B terminal on the high relay but will not when I just try to short 30 and 87 to each other.

[454headache]

Hmm, just checked with the multi, and no voltage across the 30 to 87 terminals.

[454headache]

From some mustang forums-

"1. The Taurus fan cannot have power applied to the high winding and the low winding at the same time."

I have the two relays connected from their respective + battery terminal ("B" & 30) to the battery + post. Could having these two touching each other cause this problem?

[454headache]

Here's a handy little diagram of my setup if anyone is interested in helping to explain the magic of electricity to me.

[Rickracer]

Sounds like your low speed relay is bad, not sure why the high speed isn't working, it's grounded, correct? What does it do if you put battery + to the "S" terminal? The diagram I posted feeds the low speed relay through the 87A terminals of the high speed relays, this assures that when low speed is on, high speed cannot be energized, and vice versa.
Just for a little more info, I use the A/C, WOT cutout, and fuel pump relay box from a early 90s Crown Vic or Grand Marquis to build the circuit with, makes a nice neat little package that can be attached anywhere under the hood, near the fan.

[454headache]

Well I'm stumped.

Fan Low works (connected it to the battery + for test)
Fan High works (connected it to the battery + for test)
Low Relay works (clicks when switch is on low)
High Relay works (clicks and turns on fan when S terminal connected to battery +)
Switch works only on low?

I've tested the low speed with two different 30amp relays, and they both only click, but do not turn on the fan. So its not the relay. I either connected something wrong or the switch is bad.

The high fan is connected right.
The low fan is connected right.
The high relay is connected right.

The low relay is connected right as far as the switch is concerned. I'll check for the 1,000th time to make sure the fan is connected right to it. I don't see how it could affect the high relay and stop that from working though.

[454headache]

Unhooked the low speed relay and turned the switch on low. Connected the switch lead that turned on the low sped relay to click to the high speed S terminal and that turns on the high speed.

[Rickracer]

I'd say your switch is definitely bad, and is your low speed relay connected like this?

85 - ground
86 - Switched
30 - Battery
87 - Load (Fan)

[454headache]

Yup, the relay is connected like that. I just shorted the connections n the switch, and guess what? Both fans work when I do. So I'm of to get me a new chinese switch.