Electric Fan Rewire Help Please

[twofortyrida1388]

I took clutch fan out and wired electric fan to fuel pump fuse and it works but I don't like it. When I cut the car off it takes about an extra half second to actually cut off. What are some other options for wiring this thing to run full time. Thanks

[Big Bronze Rim]

I took clutch fan out and wired electric fan to fuel pump fuse and it works but I don't like it. When I cut the car off it takes about an extra half second to actually cut off. What are some other options for wiring this thing to run full time. Thanks
Are you running the fan off the fuel pump circuit?! Thats a baaad idea if you are. What you should do is just wire up a relay so that some ignition switched source energizes the relay coil (85 is power 86 is ground on a bosch relay)and just run a fused(30A) wire from the battery to the switched poles of the relay(typically 30 and 87 on a bosch relay). That sould be much safer and eliminate the run on.

[g6civcx]

What are some other options for wiring this thing to run full time.

I don't know what "run full time" means. I assume you want the fan to run when the ignition is on.

The way you're doing it is unsafe. Without going in too much details, never ever piggyback a circuit or you risk a fire. Also, sometimes the ECU will cut out the fuel pump. This is normal operation for the fuel pump, and not how you want the fan to work.

You need to use a relay and tap an ignition circuit to trigger the relay. Before I retype, search Tech for the word "relay".

[twofortyrida1388]

Thanks for the info.

[420sx]

here ill give u a step by step.


go to autozone, go to their electrical section. pick up a 30 amp fuse link. i got a pink one ehehe. it will have copper contact plates on each side for the wires.

now, take off your steering column. this is tedious. dont break the plastic.

get a voltage lamp, ground the ground wire and try all the ignition wires till you find the one thats HOT while IGNITION is ON only. (the key is all the way turned). on s14 i think it was green but im not sure.
now, disconnect that harness from the column. pull it down so u have comfort to splice in the wire. strip the wire, wrap your fan wire (like 10 or 14 gauge. 14 gauge is best) around it. solder, wrap good in tape. put everyting back, hide the wiring nice and neatly.

now run that fan wire to the engine compartment thru ECU harness hole. u can do all this nice and neatly just take some time.
run it into the fuse box, now wire up the fuse into the wire and the other side of it run to the fans. tape up the contacts of the fuse with tape real good and lay it down in the fuse box. u can screw it in to the plastic also, theres lots of ways to do this.

now with ignition on ur fans will be on.

[xxyournoonexx]

Why not just wire it up to the temp gauge? (thermostat SU on bottom rad hose)

[g6civcx]

Why not just wire it up to the temp gauge? (thermostat SU on bottom rad hose)

I am not sure what your question is directed at, but yes, this is the ideal way. Use the temperature gauge to turn on the fan via a fan controller.

But you said "bottom rad hose". This hose carries coolant from the radiator into the engine. I am not sure how accurate your readings will be unless you have a reverse flow cooling system. Generally you want to place the temperature probe in the upper radiator hose that carries hot coolant from the engine to the radiator.

But the original poster's question is directed more towards how to draw power to the fan motor.

[twofortyrida1388]

Thanks a lot. This is very helpful info. I will get right at it.

[projectRDM]

Why not just wire it up to the temp gauge? (thermostat SU on bottom rad hose)

That sensor is only found on SOHC cars, and is a poor judge of actual coolant temps since it's measuring water after the thermostat.

[MAGILLA]

I took clutch fan out and wired electric fan to fuel pump fuse and it works but I don't like it. When I cut the car off it takes about an extra half second to actually cut off. What are some other options for wiring this thing to run full time. Thanks

run a ground wire to the negative side switch of your low cooling fan relay. it has 12v at ign. and controlls the fan anyway.