hooking thermo fan up2 toggle switch,

[shayden69]

Gday, so my thermo fan has never worked, possibly because of a faulty sensor or something i don't really no but id rather hook it up to a switch, mush easier.

Right.. i have very basic knowledge of our this works but heres what ive done.

- Cut the two thermo fan wires (1 blue 1 black)
- grounded the blue wire
- conected the black wire with an extended power cable to a 2 prong switch installed in the dash, then used a cable from the switch straight to the battery.

So it works, the fan turns on with the switch but is the correct way of doing this? is it safe? will it effect anything els in the car?

Only because ever sinse ive done this my stereo and dash lights fuse keeps blowing..

Send ur knowledge this way

[ice_cold17]

ive never done this but in my experience of electronics the black wire is usually the ground,try swapping,if this still dosent work,play it safe and wire it to your ignition switch,so that when you turn the car on the fan turns on as well

[vn1989]

put a fuse in the line from the battery to the switch and i would find an accessory wire and wire it up to that so if u forget to turn the switch off it turns off any way when u turn off ur ignition... like ur cd player for example

[matty94]

Thats the hard way of doing it and no you dont want to wire it to the ignition because after 40kph the fans useless you will just burnout your motor. There is a blue/white wire running to the computer behind the left kick panel, you cut that and run a wire to a switch then a wire to the body (earth) and then by the switch you can turn the fan on whenever the car is on, this way you dont need a fuse or anything and you dont risk burning anything out because it runs through the relay.

And yeah the way you have done it i wouldn't be surprised that things are blowing, iv seen this happen from people that have done it this way before, Id fix it before a fire starts.

[Jxw]

just put it into diagnostic mode with the paper clip method, if the fan kicks in then it's most likely the temp sensor, does it turn on when you use the AC? if no then it's some bad wiring somewhere. Check all the plugs etc.

If it is a faulty sensor it's a good idea to replace it as it'll be running rich, if the ecu thinks it's always cold, crap fuel economy and will cause more probs down the track, a $20 sensor is cheaper than replacing a poisoned/clogged cat or O2 sensor and it'll save you that in fuel if it's replaced and was the problem.

[shayden69]

hmm wel the set up is already there so mars well just install a fuse and c how it goes.

[Jxw]

well if you're going that way i'd personally put a relay up near the fan and battery and use the switch to control the relay, a relay can handle the initial current draw of the fan starting better than a switch, also you have a shorter +12V feed wire this way as to running it from the dash and back out, shorter wire means less voltage drop to the fan so it should run faster, now possibly this is why the engine fan has it's own dedicated 25A fuse up close to the battery/relay and itself, maybe holden was onto something.
The parker/instrument circuit has a 15A Fuse, so logically thinking everything already on that circuit and it's wiring draws/can handle 15A max without going up in smoke or popping fuses, now you've wired the fan into this which once again thinking logically requires 25A to start spinning, 25 + 15 = 40.... now if you rewire your dash wiring and put a beefy fuse holder in that will handle 40A then your method may work great, last time i looked under a dash the puny wires that feed everything under isn't heavy enough gauge to handle 40A.
Another option is to revert back to factory, wire a switch to the existing relay, from memory pin 85 on the relay to earth to turn on/off manually or as someone said to the blue/white wire from the ecu.

If you're intent on wiring it to run manually below is a circuit schematic to follow and put the fan on it's own dedicated wiring(no crap about my mspaint skills).

Most vehicles use switches on the negative side for safety, if the wire shorts to the body all that happens is the device turns on instead of sparks and fire.
the pin numbers are a typical holden bosch relay


also put a fuse between the batt+ and the relay for safety

I've done similar to my vl and it's headlights to run higher wattage globes and to bypass the typical fuse being melted into the holder.

And what your fuse box under the dash will probably resemble if you continue to use your current method, although the current draw wasn't enough to blow the fuse it was enough to cook it into the holder

[matty94]

hmm wel the set up is already there so mars well just install a fuse and c how it goes.

So you post a thread needing help with something (thats been covered heaps of times before) and someone tells you whats wrong and how to fix it and you dont listen and just go with the dodged up way thats making the problem worse?