Electric Fan Still Not Working

[JVBSLM]

Thanks for all of the great info on this site, this is my first post.

About 5 weeks ago I bought a reasonably nice 1999 528I with 231,000 miles. I've been over the car extensively and have most items operating fine except the electric fan. I knew that the original fan did not work, even when applying power directly to it. I purchased a new fan and replaced it today. Not a bad project when compared to changing the CCV.

Even with the AC on and lower temp switch jumpered, the fan will still not turn. I only measure 5 volts at the lower temp switch which doesn't seem like enough to feed the fan.

I checked all 4 fuses and they are good BUT.... I noticed that fuse #7 and #20 only have a single terminal in the fuse block. There is a top contact but no lower contact for the fuse. Does anybody know what these two feed? Obviously checking the fuse isn't good enough, it's important to look deeper.

Is there a relay by any chance such as under the passenger side air intake? Does the lower ambient sensor need to be at a minimum temperature before the electric fan will turn on?

Thanks for reading a long post.

[76papa]

I have the same exact car with 170000mi. You need to do a fault code check. Buy a code checker, I got mine from Bavauto for about $150. My fault code said "aux fan, final stage". I know there are 3 relays involved with the 3 stages(speeds). I believe the engine computer (DME) takes temperature information from the coolant sensor and info from the AC to control the fan. I have the added problem of my secondary air pump not coming on when cold starting. I tested the pump and it's working. I checked fuses, changed the relay, inspected the wires and everything is leading to a problem with the DME ($1200. for a new one). Before spending that kind of money, I'm bringing the car to a certified BMW shop to test and diagnose the problem. Sometimes you can't solve it on your own and best let a BMW shop diagnose the problem. Then you can still DIY to save some money.

[JVBSLM]

I went ahead and ordered the BavAuto code reader. I wasn't aware that it also read the proprietary BMW codes. I have another scanner that I've been using but it only gives basic code feedack.

I have a late '99, does it still have relays for the fan? Do you happen to know how to test them?

I bought this car from a BMW mechanic. The original owner thought that it had blown the head gasket and sold him the car very cheap. He pulled the head and found a warped exhaust valve. He did change the radiator, water pump and vanos seals while it was apart. But, he didn't change the CCV. It started smoking at start-up about 2 weeks after I bought it. The oil return hole on the bottom of the CCV was cloggede shut and oil was getting sucked into the manifold. Two of the six ports were also plugged from the plastic system that feeds into the intake manifold so the cylinders weren't all getting the same amount of blow-by. It drives much better.

[refatb]

how much did u get the car for? i managed to get one for $1,700 with 188k Miles and with a blown headgasket, but i changed everything up with a rebuilt cylinder head for $600.


Maybe you should do the Fan delete mod on your car and hook up a aftermarket temp sensor switch with a relay harness to activate the electric fan. then u wont have to worry if the DME is not turning it on. the electric fans go for $90 shipped from Zirgo with Life time warranty, and the Temp switch with harness goes for $40 shipped. look it up on eBay.

doing this mod give u about 2-3 HP gain but thats not the point, the real advantage is peace of mind, because the clutch fans are known to sumtimes seize and explode, making a BIG dent in the hood and destroying the radiator. and getting rid of the clutch fan will put less of a load on the waterpump bearings, and the waterpump will last longer.

Zirgo Fan $90 ->http://cgi.ebay.com/ebaymotors/16%22-ZIRGO-FAN-FREE-SHIPPING-LIFE-TIME-WARRANTEE-_W0QQitemZ220502317141QQcmdZViewItemQQimsxZ2009102 9?IMSfp=TL0910291810002r24323

30Amp/40Amp Relay with 30Amp Fuse $22 -> http://cgi.ebay.com/ebaymotors/40-Amp-12v-Relay-with-built-in-30-amp-Blade-Fuse_W0QQitemZ380172068245QQcmdZViewItemQQptZMotor s_Car_Truck_Parts_Accessories?hash=item5884056595

210 Degrees F sensor switch $14-> http://cgi.ebay.com/ebaymotors/210-Degree-Electric-Fan-Thermostat-Temperature-Switch_W0QQitemZ260498888520QQcmdZViewItemQQimsxZ2 0091030?IMSfp=TL0910301810004r13823




You will need a Puller type Fan on the inside that pulls air in, and a pusher type fan on the outside pushing air in. and get a temp switch that activates at 210 Degrees F, and a 30amp/40amp Relay and 30amp fuse harness and hook it all up to the fans.

[JVBSLM]

It was $3700 but I've gone over everything and probably have around $5500 in it.

I just bought and installed the OEM type fan electric and clutching fan. I suppose there is no way to wire the OEM type direct as suggested because of the DME pulsing requirement. Is it correct that the late '99 and later doesn't have a relay? I don't care if the fan has multiple speeds, I just want plenty of air blowing when sitting with the air conditioning on.

You're right, it's peace of mind, this car will last if doesn't experience another overheating episode as it must for the PO.

Question... the headlights "jiggle" when going over bumps. It's almost as if they are floating. It's really iritating. They're conventional halogen and I'm wondering if they're fixable. I've tried using tie-raps to stabilize them but that ends up changing the adjustment. Thoughts??

[MaxVQ]

Is it correct that the late '99 and later doesn't have a relay? I don't care if the fan has multiple speeds, I just want plenty of air blowing when sitting with the air conditioning on.


Question... the headlights "jiggle" when going over bumps. It's almost as if they are floating. It's really iritating. They're conventional halogen and I'm wondering if they're fixable. I've tried using tie-raps to stabilize them but that ends up changing the adjustment. Thoughts??

If your aux fan has 2 thick wires (red and black) and one thinner wire (gray I think) then it does not use relays, but a pulse width modulated (PWM) signal from the DME. (BMW for ECU)

If you have the PWM fan, then you need to check F75 BEHIND the fuses in the glove box. It is a big (1" x 1") red 50 amp fuse. Then you need to reset the "aux fan code" and all should be good.

As for you headlights, the adjusters are broken and need to be replaced. Search this site for MANY DIYs.

Good Luck!

[76papa]

[QUOTE=JVBSLM;17790725]Thanks for all of the great info on this site, this is my first post.


Is there a relay by any chance such as under the passenger side air intake? Does the lower ambient sensor need to be at a minimum temperature before the electric fan will turn on?

There are 2 relays under the passenger side air filter (E-Fuse box). Neither have to do with the aux fan. The salmon colored 5 pin relay controls the SAP, while the other one is for the wipers.

The outside air temp sensor has nothing to do with the aux fan. The coolant temp sensor on the lower hose and possibly a sensor at the AC determine when the fan comes on and shuts off.

My Haynes manual says there are relays for the fan behind the glove box.
I have to investigat this since I'm having the same problem with my '99 528i.

[JVBSLM]

I never thought about having to re-set an error code to make the fan operable again. The BavAuto code scan/re-set tool should be here by Friday and we'll see if it cures the problem.

Thanks for the guidance on the adjusters breaking, I've also ordered those. Not sure how hard it is to perform surgery on the '99 headlights but I'll find out soon.

[pbonsalb]

Try unplugging the harness at the fan and providing it with alternate 12V power and ground. If it does not spin, buy a new fan. The one on my 99 528i was dead at 120k miles. There are knockoffs on Ebay for half the price of new, but I recommend staying away from cheap Chinese knock off motors and electronics (as opposed to good ones made with strict quality controls like laptop computers under name brands). I have had bad luck with a cheap Ebay fan and a cheap Ebay starter. I bought new original for about $300. Should be good for another 100k miles.

[JVBSLM]

I received my Bavauto reader today. As expected, it had code 7D "Coolant Fan Final Stage". I re-set the code BUT the fan still doesn't work with the AC on and the temp switched jumpered. The code re-appeared which means that something is obviously still wrong. The fan is brand new but is one of the low cost Depo versions from Ebay. I don't know if the fan can be tested with 12 volts DC because of the pulse requirement. If the fan is good then would the issue be with the DME? Where is it located and is his something that could be purchased at a reasonable price used?

[76papa]

You and I have the exact same car and the exact same problem. My Bavauto code reader gives the same fault "coolant fan final stage". My fan is brand new but not from Ebay since I learned that you can't trust items purchased on ebay. The Haynes manual electric diagram for this fan shows 3 relays located under and to the rear of the glove box. You have to slide the cover towards you to get it off. Inside you will find three units with multiple wires connected. They didn't look like typical relays to me so I left it alone not wanting to mess things up anymore. I'm resigned to waiting until warm weather again since I am not using the AC and the coolant doesn't get that hot now.
I suspect the only way to solve this is to bite the bullet and bring it to a dealer shop.
If you figure this one out, please let me know.
Fanless in NY.

[titan510]

did you fix this issue? what were your findings?

I received my Bavauto reader today. As expected, it had code 7D "Coolant Fan Final Stage". I re-set the code BUT the fan still doesn't work with the AC on and the temp switched jumpered. The code re-appeared which means that something is obviously still wrong. The fan is brand new but is one of the low cost Depo versions from Ebay. I don't know if the fan can be tested with 12 volts DC because of the pulse requirement. If the fan is good then would the issue be with the DME? Where is it located and is his something that could be purchased at a reasonable price used?

[Rjim]

I received my Bavauto reader today. As expected, it had code 7D "Coolant Fan Final Stage". I re-set the code BUT the fan still doesn't work with the AC on and the temp switched jumpered. The code re-appeared which means that something is obviously still wrong. The fan is brand new but is one of the low cost Depo versions from Ebay. I don't know if the fan can be tested with 12 volts DC because of the pulse requirement. If the fan is good then would the issue be with the DME? Where is it located and is his something that could be purchased at a reasonable price used?

Just replaced my aux fan ('03 530 which should be the same set-up as yours.) The new fan comes on after about five minutes at idle with A/C on with the engine fully warmed up. It does not come on immediately. Also if your A/C is working, your aux fan should also be getting 12+ volts through fuse #75. On my car, at least, the aux fan and A/C compressor are on the same circuit.

[JVBSLM]

did you fix this issue? what were your findings?

I never got it working and have since purchased additional diagnostic software which says I have a fan final stage problem. Not sure if this means the fan itself or the ecu. The temperature would get up to 245 and the mechanical fan (Behr clutch purchased in fall) would never speed up and the electric fan wouldn't kick on. Two weeks ago I ended up getting a cheap Chinese clutch from Autozone which seems to work much better and pull a lot of air. If the mechanical fan works properly then the electric fan shouldn't be needed. Any thoughts on fixing the electric fan or what else to check? Could the final stage be bi-passed and run 12 volts directly to the motor?

[Rjim]

I received my Bavauto reader today. As expected, it had code 7D "Coolant Fan Final Stage". I re-set the code BUT the fan still doesn't work with the AC on and the temp switched jumpered. The code re-appeared which means that something is obviously still wrong. The fan is brand new but is one of the low cost Depo versions from Ebay. I don't know if the fan can be tested with 12 volts DC because of the pulse requirement. If the fan is good then would the issue be with the DME? Where is it located and is his something that could be purchased at a reasonable price used?

Make sure you bought the correct fan. Just replaced mine on a '03 530i. The "final stage", I think, is built into the circuit board of the motor. See photos. If your old fan motor doesn't look like this on the inside, your new fan motor is not appropriate for your car. 9/98 and earlier had a different set-up.