qboneus

Blue is high speed, you need to tap into the solid green wire that is housed in te same harness right next to the blue you already spliced into.

What the problem I had with mine is that the positive 12v is not switched with the ignition and the fans will continue to run after the ignition is switched off.
dead battery in the future?
the low speed is to quiet for my taste and I HAD to remedy this.
The easy fix is to take your standard bosch-style 87a spdt relay and change a ignition switched positive to a switched negative.
this is done by running your exisiting switched positive into the coil terminal #85,......... then you would tie coil terminal #86 and the switched pole terminal #30 together and attach to ground...
we have now wired the coil.
We now need to attach the ground wire we have coming from our fan relay switch to terminal #87 on our relay,..the Normally Open contact.
Terminal #87a which is a Normally Closed contact is NOT used at all as it will only be provided ground while the switched positive or terminal #85 is NOT energized, eg ignition off.

Works like a charm on my Z, the fan relay de-energizes or returns to a non-overridden PCm state as soon as my ignition is switched off.
No need for LED's, no need to remember to switch off your override.

Tal

Thanks shoebox I searched out your site and found the info I needed.
Thanks for the great service your pages offer us fbody owners!
Tal

sn8ke eatr

too confusing for me.. haha i just made my own setup with an on/off toggle and some wire from the hardware store. works fine so far.

THE_RUCKUS

make sure you fuse it.. my buddy burned up his car like that

qboneus

By switching a pre-fused switched positive to a switched negative???

There is fusing in the switched positive and ground is lifted from the fans as soon as the positive is switched off.
Tal

Oxygen454

Interesting concept. My question is, what is a DPDT? Is that the switch or a relay?
Switch right? DPDT is Double Pole Double Throw switch. that equals 3 positions. on/up, off/center, on/down.


Does anyone have a picture of this circuit built?

Oxygen454

Also could you not just run a relay and wire to your fuse panel that would have accessories? Thats how my radar detector works. You shut the car off and off goes the radar detector.

Oxygen454

I found some great info from 01Z his website under mods has some great photos but none of the actual circuit. http://www.xious.com/camaro

qboneus

Yes,.. this is exactly the concept, except that you must use the relay to change your existing switched positive+12 to a switched ground or negative as it is a ground making\breaking that controls the exisiting factory fan relays.

I may have made a typo it is actually a SPDT relay, SINGLE Pole Dual Throw Bosh style.
A DPDT is just a DUAL Pole Dual Throw.

this link may help to explain it a little better, I haven't had time to read it all myself though....

http://www.partsexpress.com/resources/relays.html



Think I figgured where the dpdt came from, the switch is a dpdt in shoebox's diagram.
the relay is a spdt..
you can research changing a switched positive to a switched negative on the net, I'm sure there will be plenty of info.

Tal

Oxygen454

So you would almost need another relay that would work as in....
car on relay gets power and switches providing a ground... (circuit/fans turn on)
when the car is off relay switches back and provides a hot 12v (turns circuit /fans off)

K totally understand... Im going to use the switch and lights, will post a pic of the circuit on the circuit board if I ever get around to building this. haha

shoebox

When the relay is off, it should provide nothing (if I am following this correctly). There is no need for any 12v.

Oxygen454

Ya no need for 12volts because the fans run on a ground to turn on. The only power you would need is to run the led's. Question, if you turn the switch to the middle does it send the fans back to normal and does the led's turn off? It would be nice to have them off in the winter so there not always on.

qboneus

Ding, Ding we have a winna!
When the switched 12v that controls the relay coil turns off with the ignition, all reference to ground is lifted, and the PCM regains sole control of the fans and all fan wiring is electrically returned to stock regardless of what the position of the fan bypass switch is.
Tal

Oxygen454

This switch should work fine?
http://www.thesourcecc.com/estore/Pr...roduct=2751533

qboneus

Yes.

Tal

Oxygen454

I see that they recommend using the tap in style wire clips to connect to the existing fan wires. Personally I would cut the wires splice them together and heat shrink them. Apparently the clips metal internals tend to rust under the engine bay even tho they are corrosion resistant plated. Also they can come loose which in this case would not be a good thing. Dirty connections are bad haha. Just my tid bit of info.