losaltos6

So i want to do a manul fan switch in my 1997 Trans am and i have no money so i have been looking up on how to do it myself, so far i have come up with this but i have no clue on what i em doing. its for OBD-1

http://shbox.com/1/fan_sw_diagram1.jpg

So what parts do i need and what are the dos and don'ts. thanks

i420tom

iTrader: (11)

i did it the real simple way

maybe not the best way for you but this is how i did it.

i used a very thin wire and connected it to each of the fan relays, then under the dash to a switch and then a ground to the switch and viola i have a fan turn on switch.

The computer sends a ground to the relays to turn them on.(veryvery low amps get pulled thru this wire, as only power needed to turn relay on not power fans) I pulled the relays out and pushed my wire in at the same and the same place the relays goes. I didnt go under the box and splice in a wire.

now which spot i placed the wire in i do not recall but the shoebox site i think shows this.

losaltos6

well iam just gonna have to find a website with a nice write up on this, i should start by buying wire and a fan switch, well thanks.bn

losaltos6

So can i use this switch for the build and reguler copper wire?

Zralou

iTrader: (3)

I used the shbox diagram. You need a DPDT (double post, double throw) switch.

Undo the retaining bolt holding the PCM, lift it out as far as the wires will allow.
Find the 2 wires needed (check shbox.com, PCM is labeled with the corresponding terminals), then tap into the wires (I used the blue wire connectors).
While the PCM is out, under where it sits there is a rubber grommet leading into the pass side interior, feed wires into car.
Locate where you want the switch (I put mine on the drivers knee panel) hook wires as described in shbox.com and ground other terminals.

Replace PCM.

Sara Lou

i420tom

iTrader: (11)

that switch is extreme overkill
just about any switch will work due to the very low ampragae running thru the wire.
i think a relay trigger wire draws less than .05 amps.

The LT1 That Could

iTrader: (3)

yes any switch will work...as long as its DPDT.

i420tom

iTrader: (11)

that switch is single pole, like the one i used but i connect the two wires from the relays together. The tutorials are not going to reccomend this but i have had no problems with it.

single pole switch= connects two wires together (ex. both my relays on one wire to ground)
double pole= connects two PAIRS of wires together independently (it is basically two switches with one switch lever) (ex. connects relay #1 to ground and Relay #2 to ground and when the switch is off the two relay wires are not conncected to each other like they are in my setup)

losaltos6

so i need a DPDT switch? well if i can use the one i get by just connecting the two wire releys together then i guess ill do it. What about a ground, how would i do something like that.

i420tom

iTrader: (11)

any metal with no coating will give you good ground.
as i said before it is not reccomened to do it my way but it has worked fine for me for 5 years

losaltos6

So i have a diagram hear that i made, is this how you did it i420Tom? and the green low speed and the blue high speed i twist together right and then the ground i just place on any metel part of my car like the inner body panals or firewall right? Also can i get 2 single pole toggle switchs and have one switch for low speed fan and the other for high speed fan or em i jsut make myself sound like a retard? Thanks

Zralou

iTrader: (3)

There are 3 relays on the fan system.

Sara Lou

losaltos6

What are they?

litch2004

iTrader: (1)

what year is your TA and how many relays do you have in the under the hood relay box? because i hjave a diagram i have drawn that uses the dpdt switch with the leds and all if you would like it.

litch2004

iTrader: (1)

just an idea

http://www.speedspecialty.com/store/...uct=mfanswitch

losaltos6

umm i dont know but my car is a 1997, yall lemme have that diagram man, thanks

i420tom

iTrader: (11)

losaltos yes that is exactly how i did it. I used relay #1 and #3

losaltos6

Wait i420tom, what do i do with the reley box man, iam useing this diagarm, i thought i was suppose to tap into the green and blue wire and send them both to my switch.

i see a black wire and the reley box, can u explain that better man, thanks

http://shbox.com/1/fan_sw_diagram1.jpg

losaltos6

so you got a wire and placed it in reley #3 and it is pretty much the green wire and you got another wire and put it in reley #1 and it serves as blue wire and then you splicedx them together at the end where you contected them to 1 pole on the switch and left the other pole for a ground right?

like this right?

i420tom

iTrader: (11)

i did it this way because i didnt want to cut or splice wires so those two spots (LEFT CENTER, when standing in front of the car, on each relay) is where the relays get thier ground to turn the fans on. When i supply ground to these two port it turns on the relays and the fans come on. I pushed the wire into the left side of each hole touching the connector for the relay and still allowing the relay to be installed. The picture does not show the relays as i removed them only for the picture but they do need to be installed after pushing the wire in.