auxiliary fan not working?

[e30Villain]

Recently my car would overheat but I fixed it with a thermostat swap. But I noticed that my aux fan never turned on. I know that at 88 degrees Celsius it's supposed to come on to help the radiator fan. My question is, can I rig it to work at all times? I searched on the forum and couldn't really find anything that helps. It would help to keep it simple as possible as I am not tech savvy.

[jlevie]

You can force the fan on by jumpering the thermo switch connector. But there's no need to do that if the rest of the cooling system is operating correctly. Though you should find out why the fan didn't come on when the engine overheated and fix that.

[e30Villain]

You can force the fan on by jumpering the thermo switch connector. But there's no need to do that if the rest of the cooling system is operating correctly. Though you should find out why the fan didn't come on when the engine overheated and fix that.

Where is that located?

And where do you recommend i get started?

[jlevie]

The thermo switch is in the side of the radiator.

[cormier]

Instead of hacking it to be on all the time might be an idea to get it fixed so it just works as it should

[e30Villain]

Instead of hacking it to be on all the time might be an idea to get it fixed so it just works as it should

I probably don't want it on all the time, I want to switch it on myself. It gets to be 100+ in so cal and id like to help the car as much as I can

[cormier]

There's tons of thread info on wiring your own fan. Any of the solutions can be used to make the existing fan do whatever you want if you want to go down that route...

I would suggest still putting it back to stock, especially if you're not comfortable with wiring it

[jlevie]

I probably don't want it on all the time, I want to switch it on myself. It gets to be 100+ in so cal and id like to help the car as much as I can

If the cooling system is working properly the car doesn't need help from the aux fan. The A/C will need the help of the aux fan, but overheating of the engine won't be a problem.

[bmwguy325is]

My question is, can I rig it to work at all times? .

The how was answer. However you will burn up the resistor if you run it all the time. Its not made for that much constant load.

I probably don't want it on all the time, I want to switch it on myself. It gets to be 100+ in so cal and id like to help the car as much as I can

A cheap way to force the fan on is use the AC switch/button. I took the AC out of my car and when hood temps rise I use the AC swithc to get that fan going.

If the cooling system is working properly the car doesn't need help from the aux fan. The A/C will need the help of the aux fan, but overheating of the engine won't be a problem.

^--this

[tonywonder]

first thing is first. check the aux fan fuse.

[e30Villain]

Today i noticed something weird. The coolant level sensor ( on the reservoir) is going bad. It was letting out coolant. I replaced it already but could that cause overheating as well?

[cormier]

If its pissing coolant/letting air in sure

I would make sure all leaks are taken care of, then flush it and bleed really well with BMW coolant and maybe water wetter. See if that alone does it.

[e30Villain]

If its pissing coolant/letting air in sure

I would make sure all leaks are taken care of, then flush it and bleed really well with BMW coolant and maybe water wetter. See if that alone does it.

It hasn't overheated ever since my thermostat change. I feel like if i left the bad sensor in, it would have. There was a pretty steady stream of coolant coming out of it. But yes i bled it again after the sensor aswell. Thanks for the help guys. I really appreciate it.

Update: Fan fixed!