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Author Topic: DIY Electric fan conversion  (Read 112179 times)

ak96ss

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DIY Electric fan conversion
« Reply #30 on: May 21, 2011, 01:31:34 PM »
Dredging this up so I can do a reality check before I start hacking the harness.

I'm in the process of fixing an oil leak on the front of the engine, so I figured I would throw in my electric fan while I was in there. I'm using an aftermarket fan, though, that is single-speed and requires a 40A fuse, so I can't wire directly to the aux fan wiring.

My intent is to remove the auxiliary fan entirely and use the red wire coming off of the high-speed relay to provide the signaling power to a relay that will turn on the new electric fan. I'll then remove fuse 3 entirely, since the wiring won't be going anywhere. I've already got the lower-temp sensor in the radiator, so the fan should turn on at 88 degrees.

Thoughts? Anyone see anything wrong with this?
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uh, it's a '91 318is, like everyone else...

DesktopDave

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DIY Electric fan conversion
« Reply #31 on: May 21, 2011, 01:36:21 PM »
Sounds good to me, can't see anything wrong with your plans.  Isn't the harness heading to the fan pretty meaty?  I'd personally skip the relays, but it'll give a good safety margin.
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ak96ss

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DIY Electric fan conversion
« Reply #32 on: May 21, 2011, 01:47:38 PM »
It's pretty good sized, but the fuse is 30A, so rather than takes chances with it I'll run a separate harness just for the fan. Overkill is better than electrical fire.

Thanks!
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ak96ss

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DIY Electric fan conversion
« Reply #33 on: May 25, 2011, 12:02:19 PM »
After further thought, in case anyone is interested, I've decided to use the black wire off of the normal speed relay as the source of my trigger for the relay. This way, the fan will come on when I engage the AC compressor as well as when the temp goes above 88 degrees.

Wired as I originally planned it, the fan would come on when it hit the higher temp on the switch and not at all with the AC, until the coolant temp reaches the higher limit. So I'll be removing fuse 18 rather than fuse 3.
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ak96ss

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DIY Electric fan conversion
« Reply #34 on: May 27, 2011, 04:27:16 PM »
OK, for anyone who is interested and before I button everything back up again, I figured I would snap some pics.

It's a 16" Flex-A-Lite S-Blade fan, part number 398 Syclone. I could do without the big logo on the aluminum plate and will likely replace it someday, but in the meantime, I'm hoping it works - it fits, anyway.

Wiring is as discussed above: the black line from the original auxiliary fan trips the relay in front of the condenser to turn on the fan. Power comes directly off of the battery block at the firewall. I pulled fuse 18 out, as it is no longer needed.
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Ivan_S42

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Re: DIY Electric fan conversion
« Reply #35 on: August 25, 2016, 05:37:23 PM »
I've bought 14" el fan on ebay for around 50euros, putted on 88C thermostat and I wasn't satisfied with the cooling.
Now I run clutch fan until I finish overhaul of engine, but I doubt that el. fan will do the job.

I'll give it a go with Spoon fan when it comes to my next try and write a review.

Cheers
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cristimm

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Re: DIY Electric fan conversion
« Reply #36 on: August 26, 2016, 07:16:01 AM »
Quote from: Ivan_S42 on August 25, 2016, 05:37:23 PM
I've bought 14" el fan on ebay for around 50euros, putted on 88C thermostat and I wasn't satisfied with the cooling.
Now I run clutch fan until I finish overhaul of engine, but I doubt that el. fan will do the job.

I'll give it a go with Spoon fan when it comes to my next try and write a review.

Cheers

You must have a problem elsewhere. An electric fan installed properly is more than enough to cool the little M42 engine.
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