Electric Fan Conversion

[ForTheBuild]

Hey all, I have been looking to swap my fan clutch out of my 2000 540i 6 speed for awhile now as the fan clutch has been bad ( permanently engaged ) for a little under a year. I've just now started to actually do the digging for the right information and kits etc. What I have found that I was thinking about doing was the Zionsville aluminum shroud and expansion tank + Spal 16" fan and single speed kit. However, I have seen some posts talking about how the Zionsville shroud takes about a month to arrive, customer service sucking, and even the product having bad welds. I have also seen mentions of a PWM controller rather than a single speed, which, as far as I understand, allows for a fan that follows the engine speed instead of only having a single speed. Has anyone had the Zionsville kit for the E39? If so would you recommend it? Is there anyone who has done a PWM controller? If so how did you do it, was it easy? All help is appreciated!

[BMW540san]

There are several approaches and ways of doing this this.
I've done 4 of these with Spal fan and wiring kits and I'm very impressed wuth the quality and performance:
https://xoutpost.com/bmw-sav-forums/...ch-delete.html
https://forums.bimmerforums.com/foru...on-97-BMW-528i

[Milanese]

Here was my conversion for comparison (not ideal, but with final budget about $300 not bad either):
https://www.bimmerforums.com/forum/s...6#post30683056

[MtnGn]

I installed the Z-ville aluminum radiator/ expansion tank with an attached aluminum shroud and spal puller fan. Works great. I have a two-speed fan wiring harness and did not install a PWM controller.

z-ville is almost non-existent with respect to customer service. And I understand why.

The wide variability in the skill and knowledge of the end-user, IE you and me, makes any customer service on the matter nearly impossible. Otherwise they would be essentially installing these things remotely via phone all the time. EVERY auto is different too, further complicating things.

Hang it all. Sell it and let the plebs sort it out. And with that attitude, its VERY difficult to find explicit, comprehensive installation instructions. Add to the matter the fact that these autos are now 20 years out of production and most of the data and detail that WAS online, has been deleted.

So, you're own your own. For the most part. Enter the knowledge and helpful individuals on this forum. Invaluable to owning these cars, IMHO. Shout out to the forum and its mods!

The PWM controller comes into its own over the dual-speed wiring harness, when the car is shut off. The PWM allows you to run the fan for a pre-set/ pre-programmed period of time after turning the car off. Without it, you either need to wire the fan so that its turned on and off via a remote switch that is controlled by you. Or you may accept the fact that when the car is turned off, the fan goes off.

[philly98540]

I use one of these little gizmos to delay the fan from starting up for like 20 seconds when I start the car, and also to keep the fan running for about 8 minutes after shutdown.

https://wolstentech.com/products/tim...delayrelay.php

Both of these times are adjustable with the little adjustment screws. Works very good for many many years now.
Its wired to the control side of my PWM controller but could be used on the low current side of a two speed set up too.

[JimLev]

I put a Zionsville radiator in about 12 years ago and a low profile Flex-a-Lite inside the shroud.
It’s controlled by a PWM controller with a temp sensor to ramp up the speed based on temp. The fan runs all the time at 1/4 to 1/3 (adjustable) speed to keep air moving under the hood until the temp sensor increase it’s speed.
I have a switch to enable the fan to run for 5 min after the engine is turned off. I generally only use it in the summer.

[ForTheBuild]

Is the 2 speed the fans' speed or is that the controller? If it is the controller, does the PWM work with the 2 speed, or does the PWM replace the 2 speed? How long did the Z-ville shroud + accessories take to get to you and how did you mount it on the rad? I heard it doesn't have proper mounts and you need to drill.

- - - Updated - - -

What is your fan setup? Z-ville? Also I see you have a S/C'd car. I am looking to do that as well, would you recommend it? Did you rebuild your engine at all?

[MtnGn]

The two speed spal fan wiring harness I received from Z-ville was essentially redundant "hot" battery lines supplying power with a temperature switch toggling between the two and an "fan off" position. The cooler of the two "on" positions for the temperature switch toggled power through an in-line resistor that knocked down amperage. The hotter of the two "on" positions for the temp switch toggled power to the fan without an in-line resistor; IE, it supplied the full amperage thus making the fan go faster. Both power lines carried a 30 amp fuse with an optional 20 amp fuse included with the harness. I went with the 30 amp fuses.

THis system is redundant from a power supply standpoint; two completely individual hot lines toggled by the temp switch through a "High" and "Low" speed relays. Another way to wire would be to use a 4-pole relay serviced by a single hot feed. Two relays come with the Z-ville kit and this does not support a wiring design through a single relay, necessitating dual hot feeds and dual relay constant power supplies. Theoretically, you could splice a single hot line and constant power line to service both relay switches but I opted not to do that. The redundancy is a little additional wiring, but that much easier to isolate and diagnose if something goes wrong.

Both hot lines tap the battery pole at the engine block. I tapped the ignition wire in the electrical box under the hood for constants on the "high" and "low" speed relays. This was done so that power to the fan switches between on and off with the ignition. Another easy power source for relay constants would be the hot feed to the starter under the engine. If you choose a constant relay supply source not toggled by ignition system, then you will need to wire a manual switch inside the cab to control on and off functions at these relays.

I did not install the PWM controller. I imaging you can source a PWM controller that drives the fan at 2 speeds, again toggled by a temp switch.

My radiator/fan shroud/ fan/ harness arrived approximately 6 weeks after online purchase if I recall correctly. Your ETA will likely be different without the radiator in your order.

Im not sure how a fan shroud would fasten to the OEM radiator. However, I did need to drill/modify my fan shroud to accommodate my particular wiring design. I anticipate yours may also require drilling to the customized conditions of your situation.

[MotorMouth93]

I have a Spal puller fan attached directly to an OE radiator core with most of the shroud cut out, then I reprogrammed the aux fan rad exit temp vs fan % tables in the DME to ramp up much sooner. The aux fan is now my main cooling fan and the Spal puller is a backup, it's held up great over the past 40,000 miles in 105F+ Texas summers. I also have an 88C thermostat and coolant temps hover around 90-93C for the most part.

To control the Spal fan I spliced a bung fitting into the radiator outlet hose and have a temp switch wired in with a relay.

Each fan is capable of keeping engine temps safe by itself so it's fully redundant in case of a failure.