» Site Navigation | | » Recent Threads | | | 1999 M3 Swap 09-07-2023 10:10 PM 06-01-2024 03:04 PM 7 Replies, 429,836 Views | | | | | | | 11-14-2007, 03:54 AM | #1 | Senior Member Join Date: Jun 2003 Location: Jacksonville, Florida Posts: 322 | Test if Fan Works? I am in the process of rebuilding my car since my accident, and I started my car for the first time in months My radiator fan worked the first day that I turned it on. Two days later, I started my car again and just let it idle, and the fan wouldn't work. My car was actually overheating some, and the fan still didn't work. Is there a way I can test if the fan works or not? It just seems weird that it would work one day, and not the next. Is there a way I can test if there is some sensor or switch or something that's causing this problem? Thank you | | | 11-14-2007, 04:08 AM | #2 | NOBODY F's with the Jesus Join Date: Oct 2006 Location: Ventura California Posts: 7,824 | Turn the A/C on and see if the fan comes on. You may have a bad temp switch if it only comes on when the A/C is on. You might also have air in your system which won't allow the coolant to contact the sensor and register the correct temp. I'd start by checking the fan with the A/C turned on and then bleed the air out of the radiator. Make sure it has cooled down before you remove the radiator cap and bleed screw! While bleeding, turn the heater on full blast and add coolant until a steady stream of coolant flows out of the bleeder next to the radiator cap. It helps if you park the car on a hill with the nose elevated. It also helps if you massage the hoses, to push the air trapped in the system to escape. Watch your hands and hair around the belts! Hope this helps, Good Luck. __________________ 4 MORE YEARS BABY!!! | | | 11-14-2007, 04:11 AM | #3 | Senior Member Join Date: Jun 2003 Location: Jacksonville, Florida Posts: 322 | Thanks. That might be it, I'll look into it! | | | 11-14-2007, 07:15 PM | #4 | Senior Member Join Date: Oct 2007 Location: Eugene Oregon Posts: 6,182 | Quote: Originally Posted by cooljess76 Turn the A/C on and see if the fan comes on. You may have a bad temp switch if it only comes on when the A/C is on. You might also have air in your system which won't allow the coolant to contact the sensor and register the correct temp. I'd start by checking the fan with the A/C turned on and then bleed the air out of the radiator. Make sure it has cooled down before you remove the radiator cap and bleed screw! While bleeding, turn the heater on full blast and add coolant until a steady stream of coolant flows out of the bleeder next to the radiator cap. It helps if you park the car on a hill with the nose elevated. It also helps if you massage the hoses, to push the air trapped in the system to escape. Watch your hands and hair around the belts! Hope this helps, Good Luck. | good info on bleeding the radiator and checking the fan i gotta remember that one | | | 11-14-2007, 08:08 PM | #5 | Senior Member Join Date: Jan 2006 Location: Cincinnati Posts: 890 | One of the fan sensors is in the passenger side of the radiator. Pull the plug off the sensor and put a paperclip in the bottom hole and one of the top holes of the plug. This will be either the slow or fast fan speed. Putting the paperclip in the bottom and the other top hole will be the other fan speed. This is the most reliable way to check if the fan is operable at both speeds. __________________ SOLD!!! 1999 332ti //M Sport Titanium Silver M3 S52 3.2 I-6 Engine, M3 Clutch w/ ti Getrag Trans, Z3 3.15 LSD medium case diff and half shafts, OEM Hatch Spoiler, Eurosport HP Underdrive Pulleys, FDM, 17" DS1 rims, M3 Front Struts & Springs, M3 Instrument Cluster, 3-spoke //M steering wheel with tri-color stitching, SSK, CCFL Angels in Depo projectors with 5k HIDs | | | 11-14-2007, 10:29 PM | #6 | Senior Member Join Date: Jun 2003 Location: Jacksonville, Florida Posts: 322 | I tested the sensor with the paper clip and the fan only works when the paper clip is in one place, and only at the high speed, so would that mean that the sensor in the radiator is bad? Also, the fan doesn't work with the AC on. | | | 11-15-2007, 02:34 AM | #7 | NOBODY F's with the Jesus Join Date: Oct 2006 Location: Ventura California Posts: 7,824 | When you turned on your air conditioner, did you here it hiss and kick on? Did it blow cold air? Open up your fuse box. Locate the two yellow relays next to the purple relay. The purple relay is your stage2 fan relay. The yellow relay in the middle is your A/C compressor relay. The yellow relay on the right is your stage1 fan relay. Switch the two yellow relays and see if the fan comes on when you turn the A/C on. They're the same part number so don't worry about messing anything up. Just make sure the car isn't running and the key is out of the ignition when you swap the relays. If your fan comes on after switching the relays and turning the A/C on, you'll know where the problem is. __________________ 4 MORE YEARS BABY!!! | | | 11-15-2007, 04:20 AM | #8 | Senior Member Join Date: Jun 2003 Location: Jacksonville, Florida Posts: 322 | Okay, I'll check that. Thanks. | | | 02-06-2008, 06:53 PM | #9 | Senior Member Join Date: Jun 2007 Location: Odenton, MD Posts: 419 | Old thread, but no one can say I didn't search!!! I've having a similar problem. When I did the paper-clip check, only the high-speed fan came on. With the car running, turning on the A/C DID make the low-speed fan come on. Right now I'm chalking this up to the fact that I had to rewire the fan (connector was bad, so I removed it and soldered the connections). It worked well for a while, but the low-speed wiring may have failed. I'll have to wait until I get home to check it. I've got a new coolant temp sensor on the way, and I'll re-bleed when I install it. Any other ideas? | | | 02-07-2008, 06:38 PM | #10 | Senior Member Join Date: Sep 2004 Location: Manassas, VA Posts: 4,129 | I'm having the same problem, just checked. The fan works with a jumper in pin 2 and GND, but not pin 3 and GND. Turned on the A/C, and the fan works. Can't be sure what speed the fan works with the jumper, or the speed it works with the A/C on. What's next, replace the radiator sensor? Quote: Originally Posted by gimp Old thread, but no one can say I didn't search!!! I've having a similar problem. When I did the paper-clip check, only the high-speed fan came on. With the car running, turning on the A/C DID make the low-speed fan come on. Right now I'm chalking this up to the fact that I had to rewire the fan (connector was bad, so I removed it and soldered the connections). It worked well for a while, but the low-speed wiring may have failed. I'll have to wait until I get home to check it. I've got a new coolant temp sensor on the way, and I'll re-bleed when I install it. Any other ideas? | __________________ 1998 (July) 318ti, 5-spd OEM Armrest Blaupunkt Heidelberg CD50 CD Player/Compact Drive MP3 Player Diamond Audio 5.25" rear speakers Navman ICN 530 GPS BMWALARM.COM (with comfort settings) after market alarm system Magnecor 8.5mm wires M-Z3 Shifter/Momo Knob Burlwood Dashboard Stromung Exhaust X-brace Racing Dynamics Front Strut Bar Carbonio C.A.I. 17" Rial Rims Vader Seats/Heated/Lumbar Support M-tech Steering Wheel/Front Sway Bar/Front & Rear Bumper Depos/w 6500K Angel Eyes/6000K HIDs Clear Corners M3 Mirrors UUC Light Weight Flywheel/M5 Clutch/M3 Clutch Slave E28 3.46 LSD/Mcoupe Cover/E30 Flanges & Halfshafts UUC S.S. Brake/Clutch Lines Hartge Roof Spoiler BavAuto Springs Bilstein Sport Struts/Shocks E46 M3 Rear Shock Mounts SPC Front Camber Kit Reiger Hatch Spoiler BavAuto Rear Camber Kit Dinan Stage II Software Turner Rear Sway Bar Reinforcements BMW E46 Auto dimming mirror with Clown Nose alarm Engine Compartment Light Heated Wiper Fluid Retrofit OEM Fire Extinguisher Da'lan Trailer Hitch Rear Sun Shade OEM Fog Light Retrofit H & R MZ3 Rear Sway Bar/ UUC Adjustable End Links Cruise Control Retrofit On Board Computer Retrofit M3 twistie style side skirts Carbon Fiber Hood | | | 03-02-2008, 07:16 AM | #11 | Member Join Date: Feb 2008 Location: Frederick Maryland USA Posts: 45 | If you tried swaping the low speed relay and the low speed still didn't work when you used a paper clip to jumper around the fan switch (as described by campaiar) the fan switch (temperature sensor) is probably not the problem. The next obvious thing to check is the continuity of the fan low speed resister mounted on the back of the fan. | | | 03-02-2008, 01:20 PM | #12 | NOBODY F's with the Jesus Join Date: Oct 2006 Location: Ventura California Posts: 7,824 | Quote: Originally Posted by JNCoulombe If you tried swaping the low speed relay and the low speed still didn't work when you used a paper clip to jumper around the fan switch (as described by campaiar) the fan switch (temperature sensor) is probably not the problem. The next obvious thing to check is the continuity of the fan low speed resister mounted on the back of the fan. | Excellent first post! You're definitely going to be an asset to the community. Thanks for joining and welcome to the forum! BTW, I just finished drinking a bottle of tequila and smoking a fat ass stogie, sorry if I sound impaired. __________________ 4 MORE YEARS BABY!!! | | | 03-02-2008, 04:14 PM | #13 | Senior Member Join Date: Sep 2007 Location: asdfasdf Posts: 10,002 | Quote: Originally Posted by cooljess76 BTW, I just finished drinking a bottle of tequila and smoking a fat ass stogie, sorry if I sound impaired. | still sounds better than some of the stuff I say | | | 03-14-2008, 03:13 PM | #14 | Senior Member Join Date: Sep 2004 Location: Manassas, VA Posts: 4,129 | Is there a part # for the fan resistor/connector? I troubleshot my system, and all the voltages are coming from the circuits/fuses. It's either the relays, or the resistor. I know someone said to swap relays, which I did, but that is not 100% conclusive. First off, what speed does the AC kick the fan on, low or high. I think it uses the high speed, which seems to be working. I can't seem to get the low speed working. __________________ 1998 (July) 318ti, 5-spd OEM Armrest Blaupunkt Heidelberg CD50 CD Player/Compact Drive MP3 Player Diamond Audio 5.25" rear speakers Navman ICN 530 GPS BMWALARM.COM (with comfort settings) after market alarm system Magnecor 8.5mm wires M-Z3 Shifter/Momo Knob Burlwood Dashboard Stromung Exhaust X-brace Racing Dynamics Front Strut Bar Carbonio C.A.I. 17" Rial Rims Vader Seats/Heated/Lumbar Support M-tech Steering Wheel/Front Sway Bar/Front & Rear Bumper Depos/w 6500K Angel Eyes/6000K HIDs Clear Corners M3 Mirrors UUC Light Weight Flywheel/M5 Clutch/M3 Clutch Slave E28 3.46 LSD/Mcoupe Cover/E30 Flanges & Halfshafts UUC S.S. Brake/Clutch Lines Hartge Roof Spoiler BavAuto Springs Bilstein Sport Struts/Shocks E46 M3 Rear Shock Mounts SPC Front Camber Kit Reiger Hatch Spoiler BavAuto Rear Camber Kit Dinan Stage II Software Turner Rear Sway Bar Reinforcements BMW E46 Auto dimming mirror with Clown Nose alarm Engine Compartment Light Heated Wiper Fluid Retrofit OEM Fire Extinguisher Da'lan Trailer Hitch Rear Sun Shade OEM Fog Light Retrofit H & R MZ3 Rear Sway Bar/ UUC Adjustable End Links Cruise Control Retrofit On Board Computer Retrofit M3 twistie style side skirts Carbon Fiber Hood | | | 03-14-2008, 05:36 PM | #15 | Member Join Date: Feb 2008 Location: Frederick Maryland USA Posts: 45 | The AC fan should come on at high speed. Perhaps someone else can help with the resistor part number. What I understand is the resistor is located on the back of the fan housing close to the fan motor. It is about 4 inches long and 1/2 inch wide cylinder with two wires coming out the top. The wires run alongside another lead coming from the fan motor to a connector on the bottom corner of the radiator. I'd guess that from underneath the car you could disconnect the connector and measure the continuity of the resistor as well as determine whether voltage is coming to the resistor when the low speed fan should be on. | | | | | Currently Active Users Viewing This Thread: 27 (0 members and 27 guests) | | Posting Rules | You may not post new threads You may not post replies You may not post attachments You may not edit your posts HTML code is Off | | | |