GTAman

iTrader: (2)

this is probably a dumb question but has anyone ever made their own cooling fan controls that actually worked? everytime i go to car stores i alway see the switches and relays and wonder if it's possible?

-GTAman

onebinky

iTrader: (1)

All that you need to do is ground out the coil wire on the fan relay and it'll kick the fans on. No extra relays are needed.

I believe the wire color you need is a green one with a black? tracer. TEST IT before you tap into it though

PyRo9862

I made my own with a cheap switch and some wire from radio shack. The switch matchs perfect with the 4th gen console too, looks like it belongs there. There are 2 wires going into a sensor for the AC that causes the fan to turn on with the air conditioner, crossing the 2 wires causes the fan to turn on, so I just spliced a wire into each one, ran them to a switch, and turning on the switch crosses the wires. This is a picture of what I did. You can also splice into the fan temp sensor wire, and just have it set up so when you turn the switch on it grounds the wire. Now i'm sure you can find these wires under the dash and do it without running wires through the engine bay, I just had to have my car working again within an hour to get back to school, so there was no time to go wire hunting.

GTAman

iTrader: (2)

i made a diagram and enclosed it in the post. is this what you were talking about when you mean "crossing the wires"?. the diagram is for the AC wire sensor technique.

GTAman

iTrader: (2)

oops:



to AC sensor
^ ^
| |
| |
|--switch--|
| |
| |


sorry this is so crude. the site wouldn't let me post my bitmap.

PyRo9862

There are 2 wires going to the sensor when they cross the fan turns on. I recall someone mentioing that some systems are differant, and when the harness is unplugged the fan somes on, i'm not sure how you would wire that up.
Here is my attempt at a diagram of what I did.
I'm not sure if this effects anything else, by telling the ecm that the ac is on though.

PyRo9862

...

White91GTA

talk to willie, he sent me very detailed instructions on how to do it. i will be undergoing the task this weekend.

screamingz28

i think one time i used a long wire to test my fan to see of it was working. i do not know if i remember correctly but if you unplug the cable from the fan and touch a wire from the fan to the positive terminal on the battery it will start the fan. it has to send too much voltage though so don't run it very long. how many volts is reguired to run the fan? you might be able to run a wire from an open port in the fuse box to a switch, and then to the primary wire to the relay, it should work as a factory fan but with a manual turn on switch. i am probably way off but it could work.

screamingz28

i think there is a total fan control article in the tech boards that describes thistotal fan control article

GTAman

iTrader: (2)

i like that idea of running it from the fuse block to the switch to the primary fan wire. please elaborate of this!

-GTAman

screamingz28

i am going to try it out and if it works with no problems. if so i will take some pictures and tell you how.

screamingz28

okay here it is. go and buy a toggle switch that has 3 hook ups on the back. usually they are numbered 1-2-3 from top to bottom. the top on mine was the ground. there should be a spot to mount the switch right under the rear defroster switch. i drilled 2 screws through the bottom of the rear def. panel to make support to hold the switch. now the fun part. take a wire from the #1 hook up on the switch and ground it. there should be a spot to ground it near the diagnostic terminal. next takethe #2 wire through the fire wall at the drivers side and route it near the battery however you decide. look at the cable that runs from the electric fan. my fan had 2 black wires running from it. one is the ground and the other should run to the relay. the relay one is the one you want. splice the two wires together. now the #3 wire should hook up to an open ignition port in the fuse block. now all you have to do is turn it on and you have your homemade fan control ! Have fun !

GTAman

iTrader: (2)

cool thanks for the run procedure. BTW, is it possible for me to just buy a toggle with 2 prongs, tap into the relay wire and connect it to the one prong and then run a wire from the other prong and ground it?

Wishmaster's87IROC

iTrader: (4)

What is the benfit of doing this? I removed my AC and the AC fan never coems on..I assume this would give you the option of haveing one or two fans going, correct? I actually had a question about this but didnt get any answers...

thanks!

vernw

iTrader: (2)

Yep, that will work, too!



- Vern

screamingz28

it does benefit some who still have AC. you can turn the fan on at any time you want and still have factory settings. it also allows you to turn it on before the water temp gets too hot in slow traffic, allowing for cooler AC temps, that way the temp does not get to 220* (I THINK IS STOCK) before the fans kick on. you can turn them on before it gets this hot so the water temp stays lower. plus it is fun to have this done just in case you do not want to by a different relay and thermostat, which is hands free operated. i just prefer to run with the factory thermostat and relay, but with a manual overide that i described above.

GTAman

iTrader: (2)

alright, i now know the right route to go. however, i still have one question left: how did you guys run the wires from the engine bay into the interior? i'm apprehensive about drilling holes in my firewall.

vernw

iTrader: (2)

On my 91 there's enough slack in the grommet behind the fuse box to slip a couple of extra wires through to the interior.

White91GTA

I too ran them through an existing whole that had a rubber grommet in it.

GTAman

iTrader: (2)

what hole was that?

White91GTA

The hole i used is just to the left of the brake pedal...pull the carpet back and then the insulation had a little half circle cutout of it and there was the hole. I think the hole i used had been drilled out prviously because the guy before me (or maybe even the owner before him) had a system in there and that is where what looks to be the power wire was run through.

vernw

iTrader: (2)

I used the existing hole that all the wiring goes through on it's way to the fuse box. Looking from under the hood, it's located just inside from the driver's side fender before you get to the brake booster, below the relays for the electric fans. Hope this helps, can get a picture this weekend if you need it.

Have a Great Day!!!


- Vern

GTAman

iTrader: (2)

Vern,

could you get me that picture please? stuff like this i need to see

divinemercy

i used the ac/heater blower switchto remotely turn on my collant fan (1986 5.0L TPI w/single coolant fan)...rewired and spliced a bit so my cooling fan will come on when the blower switch is in the high position and the function slider in any position other than off...i did this by using the high speed blower control relay to get the ground to the green/white wire of the coolant fan control relay...all splicing was done near the high speed blower relay and the blower fan speed resistor...no aditional switch to buy...no additional wires in the engine bay or under the dash...factory operation is still availible if wanted...no hi speed on the blower motor but you still have all the other blower speeds availible...when the coolant fan is manually operated the thermostat (factory 195 deg.) controls engine temp...be sure to allow the engine to acheive normal operating temp prior to operating the manual switch...email me with detailed questions at divinemercy@kc.rr.com or ask on the board...but it is kind of complicated to explain...easy to do though...divinemercy

IceManRS305

iTrader: (-1)

any way to make your fan come on for 5 minutes or so after your car is turned off? id like to have this set up with also a manual switch....ive seen these on older pick up trucks and i was trying to figure out how they were wired and what was needed to get a timed switch with also a master control switch inside the car... any ideas??

onebinky

iTrader: (1)

When you wire up your relay, pull the 12+ constant and coil 12+ direct from battery source instead of ignition.

Only downside to that is that you would have to flip the switch back off after the car is cooled.

If you want it to turn off automatically after five min., you'd have to design some kind of delay circuit utilizing a timer. I can't help you there Maybe post something up on the electronics board for that, or try a yahoo search.

IceManRS305

iTrader: (-1)

ok cool thanx alot i appreciate the info