Help me out with a weird fan issue. Turns off after 3-4 seconds.
08-29-2016, 12:25 PM
#1
Help me out with a weird fan issue. Turns off after 3-4 seconds. Ok, I'm posting in here because almost all of us are running a non-factory fan setup.
With that, I have a single 16" fan, that I wired into the factory relay setup, and it was working fine up until last week.
So, either fan or electrical issue. Put 12v directly to the fan, and it runs, so the fan is fine.
I hook up HPtuners, go into the fan section, and turn on the fan and it runs for 3-4 seconds, then shuts off, and I can hear a relay click off. So I replaced all 3 fan relays, and still the same thing.
I'm not exactly an electrician, sure I can measure voltage and continuity, and sorta understand a wiring diagram, but that's the extent of my general knowledge.
So please someone help me out. I could always just wire up a switch, and turn on the fan when I get in stop and go traffic, but I'd rather let the pcm dictate when to shut it off, ie above a certain speed.
I checked the ground under the fuse box that is in the driver's side, and went back to the ground on the battery, and there was very little resistance, and did the same with the ground on the wire for the fan plug, again, low resistance back to the ground on the battery. I checked the 2 fuses, the 10amp and the 40 amp, and both are fine.
Thanks guys.
With that, I have a single 16" fan, that I wired into the factory relay setup, and it was working fine up until last week.
So, either fan or electrical issue. Put 12v directly to the fan, and it runs, so the fan is fine.
I hook up HPtuners, go into the fan section, and turn on the fan and it runs for 3-4 seconds, then shuts off, and I can hear a relay click off. So I replaced all 3 fan relays, and still the same thing.
I'm not exactly an electrician, sure I can measure voltage and continuity, and sorta understand a wiring diagram, but that's the extent of my general knowledge.
So please someone help me out. I could always just wire up a switch, and turn on the fan when I get in stop and go traffic, but I'd rather let the pcm dictate when to shut it off, ie above a certain speed.
I checked the ground under the fuse box that is in the driver's side, and went back to the ground on the battery, and there was very little resistance, and did the same with the ground on the wire for the fan plug, again, low resistance back to the ground on the battery. I checked the 2 fuses, the 10amp and the 40 amp, and both are fine.
Thanks guys.
08-29-2016, 01:32 PM
#3
I think it's a pcm issue.
I checked the green wire going to the pcm, and with the fan off, I'm see some resistance on the line, but not open loop, but when I command it on, the resistance drops, but doesn't go to zero like it should, but when I turn off the car, it goes to open loop.
It didn't do that for fan #2.
I checked the green wire going to the pcm, and with the fan off, I'm see some resistance on the line, but not open loop, but when I command it on, the resistance drops, but doesn't go to zero like it should, but when I turn off the car, it goes to open loop.
It didn't do that for fan #2.
08-30-2016, 07:36 AM
#5
Restricted User
You can get a switch and adapter for $30 that go in the Coolant temp sensor port on the passenger head that will operate both of your fans at certain temps. Their OEM BMW fan sensors and most are 2 stage.
Pick up the 180/190 switch. Once temps get above 180, first fan kicks on. Above 190, 2nd fan kicks on. Much better than a toggle switch. Still directly by coolant temps but doesn't have to pass through the ECU first.
Pick up the 180/190 switch. Once temps get above 180, first fan kicks on. Above 190, 2nd fan kicks on. Much better than a toggle switch. Still directly by coolant temps but doesn't have to pass through the ECU first.
08-30-2016, 08:20 AM
#6
Do any tune changes prior to it all? Fans in the tuner are in a totally odd ball screen so unless you tweaked them recently I can't see how it's an ECM type issue.
It does almost sound like an electrical issue but it sounds like you have went through all of the stuff there. You follow the wiring all the way through? Don't have melted connections under the fuse box or something do you? Going through that on my TA with the headlights, thought the bulb was bad but it would flicker on, pulled off the connection and realized it was half melted for some reason.
It does almost sound like an electrical issue but it sounds like you have went through all of the stuff there. You follow the wiring all the way through? Don't have melted connections under the fuse box or something do you? Going through that on my TA with the headlights, thought the bulb was bad but it would flicker on, pulled off the connection and realized it was half melted for some reason.
08-30-2016, 11:29 AM
#7
You can get a switch and adapter for $30 that go in the Coolant temp sensor port on the passenger head that will operate both of your fans at certain temps. Their OEM BMW fan sensors and most are 2 stage.
Pick up the 180/190 switch. Once temps get above 180, first fan kicks on. Above 190, 2nd fan kicks on. Much better than a toggle switch. Still directly by coolant temps but doesn't have to pass through the ECU first.
Pick up the 180/190 switch. Once temps get above 180, first fan kicks on. Above 190, 2nd fan kicks on. Much better than a toggle switch. Still directly by coolant temps but doesn't have to pass through the ECU first.
Do any tune changes prior to it all? Fans in the tuner are in a totally odd ball screen so unless you tweaked them recently I can't see how it's an ECM type issue.
It does almost sound like an electrical issue but it sounds like you have went through all of the stuff there. You follow the wiring all the way through? Don't have melted connections under the fuse box or something do you? Going through that on my TA with the headlights, thought the bulb was bad but it would flicker on, pulled off the connection and realized it was half melted for some reason.
It does almost sound like an electrical issue but it sounds like you have went through all of the stuff there. You follow the wiring all the way through? Don't have melted connections under the fuse box or something do you? Going through that on my TA with the headlights, thought the bulb was bad but it would flicker on, pulled off the connection and realized it was half melted for some reason.
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08-30-2016, 12:39 PM
#8
TECH Senior Member
iTrader: (7)
Would go through and double them all the wiring and the relay terminals. Look for signs of heat and melting. It's possible that the relay terminals are making a bad contact, causing heat, and causing the relay to shut down.
Andrew
Andrew
08-30-2016, 01:16 PM
#9
Good idea. I did connect to the backside of the relays and ground out each one that the pcm sends a ground signal to, and the fan would turn on and stay running, hence why I'm thinking it's a pcm related issue, that for some reason, even though it's being told to turn on the fan, for some reason, after the short period of time, it shuts off.
08-30-2016, 02:13 PM
#10
Restricted User
Does it only shut off using the PCM controls in the scanner?
Have you tried letting it warm up to temp and seeing if the fans stay on for more than a few seconds?
If the car isn't running yet, you can put a resistor inline on the coolant temp signal wire to trick it into thinking its running hot, to see if the fans stay on.
Have you tried letting it warm up to temp and seeing if the fans stay on for more than a few seconds?
If the car isn't running yet, you can put a resistor inline on the coolant temp signal wire to trick it into thinking its running hot, to see if the fans stay on.
08-30-2016, 03:41 PM
#11
Well, this all started when the car began to overheat and I realized that the fan wasn't turning on. That's when I pulled out hptuners, the coolant temp was 225, which I have the fan commanded on at 180, so I went in and cycled the power with hptuners and discovered the issue.
08-30-2016, 10:33 PM
#14
Mine does this with the vcm controls on certain versions of hptuners. My fan runs when it's supposed to but if I try to turn the hi and low fan on at the same time with vcm controls it runs for a few seconds and shuts off. It's an hptuners issue I believe. Also with this version of hptuners I couldn't use vcm controls to play with timing or afr.
08-31-2016, 04:28 AM
#15
Mine does this with the vcm controls on certain versions of hptuners. My fan runs when it's supposed to but if I try to turn the hi and low fan on at the same time with vcm controls it runs for a few seconds and shuts off. It's an hptuners issue I believe. Also with this version of hptuners I couldn't use vcm controls to play with timing or afr.
08-31-2016, 06:42 AM
#17
Restricted User
https://www.summitracing.com/parts/prf-30113/overview/
A little expensive, but threads straight into the passenger side head coolant port and controls the fan.
You can get OEM BMW ones a lot cheaper but they are typically M14 and will need an adapter, but they are dual stage and will control both fans at different temps. Just cut the ground on the relay going to the ECU and run it through the sensor.
A little expensive, but threads straight into the passenger side head coolant port and controls the fan.
You can get OEM BMW ones a lot cheaper but they are typically M14 and will need an adapter, but they are dual stage and will control both fans at different temps. Just cut the ground on the relay going to the ECU and run it through the sensor.
08-31-2016, 08:07 AM
#18
I'm going to have a couple local buddies take a look at it first, because there is a good chance I'm missing something stupid, but if I can't figure it out, I'm going to go that way and just ignore the pcm.
THanks for the link.
THanks for the link.
