Done! Electric fan speed control...I'm not an electrician in any way, shape, or form

[wpoll]

Originally Posted by workingonit

...
[*]4) thagomizer (label for a baseball bat with multiple long spikes driven thru it...for campground protection against Bigfoot; see Gary Larson cartoons for the name's origin),

...

Worth posting here, since it is classic Larson... and it seems the scientific community have now officially adopted this name for the tail of the stegosaurus...

Originally Posted by workingonit

... So, now, I was considering a label for the black "mystery box" in plainsight on my X5 console, just because. I thought of several other technobabble names, but instead, decided upon "Lüfter Geschwindigkeitsregler" (fan speed controller, in German). Why not ?

Perfect!

[workingonit]

I went outside to afix the label to the controller (such a long Dymo label that it had to go on diagonally), and then searched in my parts bag in the trunk, and found the original Derale 16738 kit's push-in thermostatic sensor (never used, because I bought an adjustable one, separately). I took apart the top of the radiator, removed my Flexalite fan/shroud assembly, and saw why I chose not to use the push-in thermostatic switch...my Nissens radiator has super-fine gaps between fins, and the push-in won't go in.

When I installed the adjustable unit, I had the same problem (now that I remember), and attached (wedged, actually) it to the aluminum/plastic seam just below the top hose inlet. Then, I guess, I lowered the activation threshold temperature until the switch would turn on the fan. I think it ended up turning on at 183-186F IIRC. But, the push-in, non-adjustable T-stat switch wouldn't fit in the same spot (the switch-head was too large), so I used picture-hanging wire to bind the push-pin to the aluminum frame atop the radiator, next to the inlet hose) then secured it there with a lot of aluminum-foil duct tape (to hold it in place, plus to transfer more heat to the switch), It should've worked, but didn't.

I got out my laser temp gun and measured the radiator temp in several spots (when Torque Pro said the coolant was at 190-194F); the switch location was 140F, the middle of the radiator (3" down from the top) was 157F, and the bottom of the Radiator (near the outlet) was 128F. Where could I alternatively mount my next thermostatic switch, to get a hot reading quickly (possibly putting a probe inside the top radiator hose, as I've read that some guys do)?

Here's the switch I'm looking at, to do just that, with the added benefit of having a much wider starting range:
https://www.amazon.com/American-Volt...e%2C134&sr=1-3

I'm not tearing it down again, so if for some reason the next switch doesn't work, then it's full manual operation from then on. It's a shame, that I can't utilize the same sensor that turns on the Auxiliary fan when the coolant gets to 190F (even with the A/C turned off, completely). I'm sure it gets a turn-on signal via Ibus or Kbus, so I can't just tap a wire and run it to the Derale relay, can I?

[80stech]

You want the fan to be controlled by the rad outlet temp not the hot inlet or engine temp. The fan only needs to come on if there isn't enough natural cooling to keep up. You could use the temp sensor for the aux fan but you would need a voltage comparator circuit to drive the relay so probably not realistic or worth the trouble.

[workingonit]

Originally Posted by 80stech

You want the fan to be controlled by the rad outlet temp not the hot inlet or engine temp. The fan only needs to come on if there isn't enough natural cooling to keep up....

I'm old-school, coming from many years of working on and racing hot-running, high-compression mostly Chevrolet V8's. They usually had cast iron blocks & heads, and keeping them cool was a real problem.

It didn't help when I'd stuff a bigger engine in, without room for a bigger radiator, but there were work-arounds to help cool the engine (lower-temp T-stats...or flow restrictors, adding a monster truck fan, and running special cooling additives to the "plain water" required by the tracks). But when the compression went up above 12:1, and I switched to expensive aluminum racing heads on my BBC 427 (first iteration), I pulled out all the stops to keep it cool.

I used the best Cometic MLS head gaskets, installed an oversized Summit Racing aluminum radiator (w/o trans cooler; it got its' own standalone B&M stacked-fin radiator with an attached Hayden fan), ran two 14" Flexalite fans (manually controlled), and used a 55 gph Meziere electric water pump. I monitored cylinder head temps, water temp at the thermostat housing, and radiator inlet temp, all to determine when and if I needed to switch on/off the fans & water pump (same for the transmission cooler fan). I had no alternator (I used two large batteries in the trunk, charged between rounds, to power everything, so I had to conserve my electrons).

All that aside, I also had a few Chevy V8 street cars & trucks, often high performance and some used for towing, so I added supplementary electric fans, sometimes with thermostatic switches, sometimes fully manual. When I did use the thermo switches, I always inserted the push-pin probe into the radiator fins, as near to the radiator inlet, as I could. All the manufacturers of those thermo switches insisted to mount them in that location. Who was I to argue?, especially since they seemed to work fine.

New cars, and European cars, place their thermo switches at the radiator outlet, like you said to do. So do many on the internet. But, as I said, I'm more concerned with the temperature of the coolant as it exits the engine (remember my monitoring the cylinder head temps and Thermostat housing temp?), than with how cool the coolant is, going back into the engine.

That's why I'll still place the new probe in the top hose, and use it to switch on the Flexalite fan earlier than the fail-safe Auxiliary fan gets triggered. I can't/won't depend on a possibly 22? year-old Aux fan to start cooling the radiator, if there's no semi-automatic way to have a thermo switch trigger the aftermarket fan. I'd still like to use the manual override as a backup, and not fear forgetting to turn it on (I'm a senior, and blonde, hahaha). Multiple ways to operate the system is a plus in my book.

[workingonit]

Originally Posted by workingonit

...I'll still place the new probe in the top hose, and use it to switch on the Flexalite fan earlier than the fail-safe Auxiliary fan gets triggered... I'd still like to use the manual override as a backup, and not fear forgetting to turn it on... Multiple ways to operate the system is a plus in my book.

too much time to think, complicating a simple plan, and too little money to do it the right way...I'm waiting for my "allowance", before I order the next round of parts for this project. I would've been thru if the thermostatic switch(s) hadn't suddenly failed. The original push-in T-stat switch just can't read enough heat to turn on (it needs 185F), because it won't fit into the radiator fins (too tight).

While waiting for the American Volt adjustable switch, I investigated the possibility of using a contact thermostatic switch, made to close the circuit at a lower (than 185F) temperature, and attach it to the radiator frame near the inlet hose (it worked with my capillary switch for 2.5 years), but farther away than the earlier one. So, since my infrared temp gun read 157F at the new location the other day, I guess I'll order the 50C/122F switch, and move it slightly away from that spot, until I find the sweet spot (when the Torque Pro app says the engine coolant has reached 175-180F, this switch should turn on the fan).



This experiment will cost me about $27. The adjustable thermo switch and on/off override switch I'm ordering are another $35. If my CFO doesn't pitch a fit (we owe taxes, somehow, due to her medical expenses and bad choice of govt. insurance), I'm also ordering the AstroAI AC/DC clamp meter I've been putting off getting (there's always something else, you know), because I'd like to know how much current the fan/speed control/thermo switches are drawing (maybe too much for the old themo switch?).

I intend that the adjustable switch be the primary (my first one failed), and the contact thermo switch as the backup. With that pair of switches hopefully working, and the override switch replaced with a new one, as well, perhaps I can put this project to bed, finally (haven't I said that before?).

[bcredliner]

https://xoutpost.com/bmw-sav-forums/...lutch+electric

Still working fine.

[workingonit]

Originally Posted by bcredliner

Still working fine.

I had no doubt that your fan installation would still be working, despite the failure of your first controller, and the differences between our two installations.

I bought a higher cfm Flex-A-Lite 16" fan (your model #118 is rated at 2500 cfm, while my model #238 is rated at 3000 cfm...both specs as shown on the Summit Racing website; other than the cfm ratings, both fans are identical), so there's probably quite a difference in the noise level at max rpms between the two models.

Reducing the noise level at stoplights, or when idling, was my intent for the addition of the fan speed controller, and now the replacement of the failed Hayden adjustable thermostatic switch. I was on a budget in 2021 (and will perpetually be on one), when I installed the fan on my 3.0i, so I bought only what I knew I needed at the time, choosing to add on later "improvements", as need and resources dictated. I would've liked to use all Flex-A-Lite componentry, but I was making-do. I'm still making-do.

Makes me long for my working & racing days, when I would & could buy top line parts for my cars (sometimes, I traded old parts and/or my labor for some parts, though).

I should actually get it done, in 2 weeks...my previous announcement that the project was done, was premature. I've met with problems in the few days since then.

• 1) I had income TurboTax problems and a huge check to write to the IRS,
• 2) my AT&T broadband router fried (down for days, while my Boost Infinite/Samsung S9+ phone combo became simultaneously incapable of going online, first noticed when the home internet failed),
• 3) the power failed for a half a day (happens about 10 times a year in my area), and
• 4) my Dixon 3304 zero-turn mower suddenly wouldn't engage the blade, though I had repaired and tested it a day prior...sharpened blade, new belts...it worked perfectly).

It's been a trying month and a half, especially the last week. Furthermore, the wife went down to her family compound/ranch, yesterday, to take care of her mom, and about 15 animals, while the others all went to Disney/lalaland whatever (I'm not a Disney fan, at all); she'll be gone 10 days. Meanwhile, I'm coming down with the flu, or my allergies have gone nuclear, and I have to care for 3 dogs, 4 housecats, 7-10 semi-feral cats, and her 4 free-range (means they eat catfood & destroy the garden) chickens. Oh, did I mention her African Grey parrot? No rest, no fun.


from the 2015 thread

Originally Posted by bcredliner

...I choose to purchase a Flex-A-Lite Slimline fan model number 118 costing $179, their adjustable temperature control module model number 31148 at $50 and associated wiring harness at a cost of $48. I was unable to find the CFM rating of my clutch fan. The model 118 is rated at 2,500 CFM that will handle up to a 600HP big block. The fan draws 18.5 amps.

fan differences: I bought a higher cfm Flex-A-Lite 16" fan (your model #118 is rated at 2500 cfm, while my model #238 is rated at 3000 cfm...both specs as shown on the Summit Racing website; other than the cfm ratings, both fans are identical), so there's probably quite a difference in the noise level at max rpms between the two models.

more differences: On today's Summit listings,

• 1) the 118 fan is $36 less than the 238 similar differential in 2021,
• 2) the adjustable temperature control module model number 31148 at $50 is now listed as 31147 @ $47, my Hayden was only $20 in 2021, though the one shown in your photos is PN#30332 @ $120,
• 3) your associated wiring harness is still about $48-50, while I paid $30 for my Derale harness, in 2021.

The performance of the fan has exceeded my expectations. There is a noticeable difference in how fast the engine revs which should transfer to improved performance. Apart from performance I really like that the engine reaches operating temperature faster and the normal radiator temp is maintained after the key is removed. (The fan will run for about 20 seconds every few minutes for around 20 minutes. The battery handles the usage just fine)....

performance differences: my engine is also noticeably faster to rev, and I suppose it reaches temperature faster, too, and maintains temp at 190F perfectly, but my Hayden adj. thermo switch never cycled as yours did (the #30332 as shown probably has hi/low adjustments, whereas the Hayden is on at 185F, off at 170F, which was never letting it cycle). I don't expect my soon-to-be ordered replacement thermo switch (2 types) to cycle the fan on/off much either, if at all, but I'll have speed control covered, at my fingertips, which will do much the same thing.

Recently the controller fried. I don't know the cause although the previous day I was re-checking the original setting by dialing the temp that the fan engages higher and lower. I replaced the controller with the same model. My guess is that particular controller was faulty.
maybe all thermostatic switches/controllers fail eventually, but spending $25-30 for a replacement beats $120, at least for me

The fan I chose is a straight blade 16" fan that covers more than 70% of the radiator required for the fan to cool to maximum potential. I used the stock shroud with no modifications.

same, same

I placed the controller on the driver's side near the primary 12v source....
The controller has a radiator probe that is pressed between radiator fins. The probe spreads the fin to a slight press fit but not enough to cause damage. There is no concern for the accuracy of the probe because the controller is adjustable. I have the controller set to power the fan just prior to when the aux fan starts up when the A/C is off....

differences, again: my first controller was installed in the empty space near the SAP (more room in a M54 engine bay), but the probe was routed to run just below the upper radiator hose, along the seam between aluminum radiator structure and the plastic side tank (I tried and failed to insert either of the temp probes between fins safely, so that was the hottest location I could afix the probe to); I never tried to correlate the functions of aftermarket fan with the factory Aux fan.

[workingonit]

Originally Posted by workingonit

... I bought (buy) only what I knew I needed at the time, choosing to add on later "improvements", as need and resources dictated. I would've liked to use all Flex-A-Lite componentry, but I was making-do. I'm still making-do.

Makes me long for my working & racing days, when I would & could buy top line parts for my cars (sometimes, I traded old parts and/or my labor for some parts, though).

I should actually get it done, in 2 weeks...my previous announcement that the project was done, was premature. I've met with problems in the few days since then. (yada,yada)....

Wife's back in town, so I can get some rest from caring for our menagerie alone, and can use my monthly "allowance" to buy the parts and tools I need to finally complete this project (I had previously wanted to order the parts 11 days earlier, but extra expenses got in my way). And, as usual, I bought her $40 of cookbooks (I always get her something she'd like...from her wishlist, just because), at the same time.


The main repair item (adjustable thermo switch) won't be here for over a week, so I'll probably be sitting on my hands, fidgeting, while waiting.

I guess I've been spoiled by the semi-instantaneous gratification that ordering online often brings, compared to the days (pre-internet) where we'd have to snail-mail orders to distant suppliers, or drive all over to go to nearby brick-and-mortar shops/warehouses to look over their stock of parts (nearby could mean 100 miles!). And endless hours of phone calls, only to often get a moron on the other end, or get put on hold for hours.

So, I guess I'll just wait in silence, care for my critters, and be happy for the relative quickness of parts coming to me. I'll finish the project, eventually.

[workingonit]

The adjustable thermostatic switch arrived late yesterday (earlier than expected), so I can remove the not-working switch and wiring from the X, and install the new parts. Tomorrow, because it's wet, rainy, and there are too many mosquitoes out for me to work on it today. And, there's another problem to address.

Though it's been almost a week since the wife came back from the ranch, she just told me of a problem with the HHR Panel she drove down there. No A/C. Funny, it was working perfectly a few days before, both on her drive to the ranch, and for me, on a short trip to the Walmart, two days before her trip. Sudden and complete loss of refrigerant? Why?

So, just before dark last night, I took my Foxwell (I've got BMW and General Motors software loaded) out to the HHR, and scanned for problems (none detected), looked at live data, and ran active tests on the A/C. Everything looked and worked as it should, except the hi-side pressure sensor was way off the expected value.

So, I'm getting dye, leak sealer, and R134a for the HHR tomorrow, and more Dexcool for the radiator (low level), and I'll work on it AFTER the X5. The wife should've told me as soon as she got home, and the HHR Panel is the back-up back-up vehicle for both of us (she has her Lexus and her GMC 1500 truck, I have my X5 and my chevy 2500HD truck), so it can wait awhile.

The HHR Panel sat for several months a few years ago, after it lost the A/C (my Foxwell reset the hi-side pressure switch at that time...coincidence??). This time, I don't see the same problem, but it'll have to wait for repair. I want to finish the X5 fan project first.

[workingonit]

Hot and humid weather, with no breeze at all, made working on the X5 a chore, but I was determined to complete the fan speed controller project today, and did.

I quickly added the new manual override switch, then tackled the non-working thermo switch problem. I had really over-secured the last switch (non-adjustable) to the radiator frame, too well, and it took me quite a while to remove my work, and install the replacement adjustable thermostatic switch (it's located eactly where I had the first adj. switch, so I used the existing wiring, which I fortunately didn't cut or shorten for the non-adj switch).

I set the new switch to turn on when the coolant temp reached 174-176F (I was using Torque Pro on my dashboard tablet, so I was away from the screen as the fan switched on). I marked the dial & bracket at 175F.

I decided to not use the mechanical thermo switch yet, and keep it as a backup in my "project parts" bin. The last Adj. switch lasted me 2.5 years, until I broke it (perhaps by over-adjusting it, twisting it too hard) about three weeks ago, and broke it, so if I just leave this one alone, maybe I can depend on it for another 2.5 years?