2005 X5 4.4 – can I force the electric cooling/radiator fan to be on?
 

I have a 2005 X5 (E53) 4.4 (N62) with about 170,000miles (has all the options)

I recently installed the bimmerfix stent to fix the leak in the coolant pipe underneath the intake and that fix seems to be perfect. Also replaced the water pump with a new one.

Live in Lake Havasu City, Arizona and it is starting to warm up with the summer highs often hitting 120F.

The car has sat for 7 months but now that it is getting warm, I would like to drive it again.

1. When I start the car, I have the AC turned on but ‘generally’ the interior AC/Heater fan has not been coming on, this is sporadic as it does turn on from time to time but most of the time, it does not matter how I try to manipulate the fan speed or temperature settings.

a. Could this be an indication of the ‘final stage resistor’ needing replaced.
The AC/Heater fan never runs with the key off though.
b. Do I need to order some canned air to clean out the little vents on the
digital temperature control panel. Sunroof has been tilted open and
there is lots of dust inside the car.
c. Does the interior AC/Heater fan really control when the main electric
cooling fan attached to the radiator turns on?
d. Could this be an indication of air still in my cooling system as if I did not get it bled enough when I refilled it and somehow the car is smart enough when there is air in the system, the fan
will not operate? I ask since last summer is when the AC/Heater fan was getting sporadic and I was needing to add coolant pretty much every time I drove it until I just parked it.
e. Any other thoughts/ideas of things for me to check?

2. The main electric cooling fan that is attached to the radiator does not generally turn on either – that is why I turn on the AC as it is my understanding when the AC is on, the main cooling fan should also turn on. Once in awhile that main electric cooling fan does turn on but it does not seem to be at full speed (this is even when the temp gauge is showing normal operating temperature pointing straight up)
a. Is it possible for me to ‘hotwire’ the main electric cooling fan to be on
all the time? I know I would need a switch of course but is it possible
for me to just force it to run at full speed with a hotwire? It really will
be a hot summer here with temperatures normally around 100F-120F. –
I THINK THAT IS MY MAIN QUESTION RIGHT NOW, CAN I JUST FORCE
THIS FAN ON SO THE CAR DOES NOT OVERHEAT?

I have taken the car on a short drive around the neighborhood and gotten the temperature up to normal operating temperature (gauge pointing straight up) and the AC/Heater fan never kicked on the main electrical cooling fan was not operating either so I shut it off without letting it run further.

I have also kept an eye on the overflow tank and have not needed to add coolant in the several times I have started the car, let it get up to operating temperature, messed with the AC/Heater controls and shut the car down.

The battery was dead for awhile but for the past several weeks, I have kept it on a 2 amp charger so I do not believe that to be a problem. – and the car starts right up when I disconnect the charger.

Thanks to anyone who has any ideas or suggestions, I am used to a small block chevy motor in a 66 Impala where everything is easy peasy without all the computers and stuff. The Impala is a convertible and it is going to get to hot to drive the thing for awhile!

Matt

take control of your fan, or fans
 

I come with a similar automotive familiarity, having just traded my '66 Chevelle drag racer (long-unused, in the garage) for my new-to-me '01 X5 3.0i. The first thing I did (after getting the semi-functional key situation fixed) was to replace my loud, cracked, and about-to-fail viscous fan assembly with a 3000-cfm Aftermarket fan (Flex-a-lite 238, 16" diameter puller) from Amazon (despite their statement that it doesn't fit my X5...it does). This thread contains much info https://xoutpost.com/bmw-sav-forums/...ctric-fan.html

I have used aftermarket fans for years, from Flex-a-lite, Hayden, or Summit Racing (plus some used fans sourced from other vehicles) on my long list of cars & trucks I've owned (mostly from General Motors), if there was inadequate cooling IMO.

If there was a hint of overheating with the factory fans, I would supplement it with an added electric fan, or even a better radiator, if necessary. I used to try different mechanical fans, but they never worked as well as electrics, which I could control by auto-thermostats or override switches.

Presently, I'm satisfied with the factory fans on my current GM stable (two have viscous fans, two have electrics), but I had read enough about the X5's inaccurate 3-stage temperature gauge (too cold, just right, too late), and the possible damage caused by the viscous fan exploding, so I bought a higher-capacity cfm fan than I needed, and use Torque Pro to get accurate coolant temperature readings. It gets quite hot in Texas, too, so why take chances?

I had confirmed that the auxiliary fan worked as it should, or I would've replaced it too, but now the new electric puller fan is set to turn on at about 175F, and while driving, it maintains the coolant at about 194F +/- a few degrees. I have an override switch if the auto-thermostat fails to function (I watch the Torque Pro display to see), and I've added another device to allow the fan to keep running after the key is switched off, without drawing down the battery (regulated by both time passed, and minimum battery voltage reached). I think the X5 is ready for summer.

I don't think this response is what you're asking for, but if you don't find that solution, you canalways take full control of both "electric" fans with just a couple of added switches.

a. I have an 04 n62 4.4. I'm pretty sure both times my FSR went out, there was no activity from the fan. It has been over a decade since I replaced the second one.

Once you get the fan running, which could be as simple as cleaning out the small vents on the AC control panel with air, as you mentioned.

e. Have you checked the refrigerant in the AC system? I'm now annually charging up my system with AC Pro. First I got the kit with the hose and now use the high-mileage variant:

https://www.walmart.com/ip/A-C-Pro-A...0-OZ/353326131

https://www.walmart.com/ip/Ac-Pro-A-...nces/444741999

I use an infrared temperature gauge at the center vents with them set to the blue dots, both temperatures set to 60 and fan on max. I do it in stages, short bursts of refrigerant, until the temperature out of the vents is in the low 40's.

2005 X5 4.4 – can I force the electric cooling/radiator fan to be on?
 

You cannot Hotwire the aux fan to airways run as it runs from a PWM signal. (I mean people *have* made PWM signal).

A few things;

1) if you can't set the HVAC blower to any speed the FSU is shot

2) the aux fan will come on at a lower temp when AC is engaged (or would never get AC at a stop light)

3) unplugging the ac pressure sensor should engage the aux fan it's the main way people test it

4) if the aux fan fails self test at start, the AC won't run. It is possible for the fan to pass the test but not work, no idea how but I've seen it.

4.5) if ac doesn't run, aux fan often won't kick on because the couch fan does a good enough job.

5) the clutch fan should keep the car from overheating other than extended period of idle even at 120F. 220-120=100, 220-90=130. it's only 30% different between 90 and 120 ambient.

6) the best way to clean the interior temp sensor vent is a gum proxabrush (mini toothbrush for between teeth). Also the best tool to clean a phone charging port!

7) the temp indicator on the dash is not a thermometer unfortunately. Itt points straight up over about a 40C range is temp! Think of it as a trinary indicator 1) starting to warm up 2) mostly warm but no guarantee at operating temp 3) overheated, turn off engine immediately or warp your head.

Learn to use the hidden menu you can see the real-time coolant temps and see what I mean.

Even with the AC on, it's normal for the aux fan (at radiator) to not run unless you are not moving. Usually 5-8 minutes of idling when ambient is high like 100 will be enough to get aux fan to kick on.

You should also see it twitch at start: have somebody else start the car while you are watching the aux fan. It should move a few degrees and stop. Part of the startup self test.

A couple things that may help. INPA or BMW specific software can force the fan on at whatever percentage you request, I.e. 20% or 100% etc. My Foxwell NT520 can do it and my laptop with INPA. Good for fan diagnostics.

Also, the LCI X5s (facelift like yours) have this dumb variable valving on the AC compressor. So just because you push the AC button, doesnt necessarily mean the fan will come on. Threw me for a loop the first time i realized that..

Update - thank you to everyone for your thoughts on my issues.

I just replaced the FSR with one off Amazon and the AC/Heat interior fan works as it should and the AUX fan kicked on as it should!!!
Going to give it a test drive at some point to see how it goes.

Andrewwynn - thanks for the mention of the hidden menu. On mine it is very difficult to read. Once I hooked up a OBD2 scanner from Oreilly's to read some codes and it blew that part of the screen out. The information is still there if the sun hits the screen correctly or if I use a flashlight from the side. I will wait for better conditions for actually being to view the information but the hidden menu should come in quite handy!

There are incandescent bulbs that light that part of display. It is not a difficult task.

LOL... that might be the easiest job in the history of BMW, ordered some bulbs off Amazon, found a short video on youtube and 5 minutes later all fixed. thank you Andrewwynn

I ran the car today for about 16 miles while keeping an eye on KTMP and it would hit 105/107 (which I read is normal) then would go back down to 93 the creep back up then back down. So, I believe my problems seem to be fixed! Even filled it up and ran it thru a car wash so I can drive it. Highs will be around 100F for a few days so will take it out for happy hour and keep on eye on the temperature. I work from home so really do not drive that much but gotta get out for a beer which is 6 miles away.

Thank you all for your input!