Fan issue - they just wont turn off
04-13-2011, 08:29 AM
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Fan issue - they just wont turn off Car is a 96 miata with an LS2 from a 2006 GTO. I have put two spal fans on it and wired them together to the low speed fan wire. They turn on when manually aske them to with HP Tuners but are not on when the car is in the acc position.
When the car starts they turn on and never turn off. Help. I don't want my fans on when it is cold or likely on highway speeds. I have tried turning off code P0532 and P0533 but that didn't work.
Also tried putting 0 in the first cell on temps and 100 for the rest and that didn't work. I have gone trough hundreds of threads looking for a solution to no avail. I have posted to HP Tuners again to no avail.
Do you have any suggestions or direct me to another resouce? Frustrating issue to be sure but know it must be simple. For some reason the PCM thinks it needs to turn them off likely as a saftey default because it isn't detecting something.
Cheers.
When the car starts they turn on and never turn off. Help. I don't want my fans on when it is cold or likely on highway speeds. I have tried turning off code P0532 and P0533 but that didn't work.
Also tried putting 0 in the first cell on temps and 100 for the rest and that didn't work. I have gone trough hundreds of threads looking for a solution to no avail. I have posted to HP Tuners again to no avail.
Do you have any suggestions or direct me to another resouce? Frustrating issue to be sure but know it must be simple. For some reason the PCM thinks it needs to turn them off likely as a saftey default because it isn't detecting something.
Cheers.
04-13-2011, 10:36 AM
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"To the low speed fan wire", fine. From there, to what?
Do you know your circuit?
My advice is to set the tune up for no E-fans, and use
thermostats (see Digi-Key.com) epoxied to the radiator
to run fan relays high and low. The stock scheme is just
stupid. Your fans should be maintaining radiator core
temp, not head temp (that is the thermostat's job, the
radiator core needs to stay well below setpoint so you
have some authority and reserve).
Do you know your circuit?
My advice is to set the tune up for no E-fans, and use
thermostats (see Digi-Key.com) epoxied to the radiator
to run fan relays high and low. The stock scheme is just
stupid. Your fans should be maintaining radiator core
temp, not head temp (that is the thermostat's job, the
radiator core needs to stay well below setpoint so you
have some authority and reserve).
04-14-2011, 02:57 PM
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"To the low speed fan wire", fine. From there, to what?
Do you know your circuit?
My advice is to set the tune up for no E-fans, and use
thermostats (see Digi-Key.com) epoxied to the radiator
to run fan relays high and low. The stock scheme is just
stupid. Your fans should be maintaining radiator core
temp, not head temp (that is the thermostat's job, the
radiator core needs to stay well below setpoint so you
have some authority and reserve).
First off thank you for responding and trying to help. The wiring in place sees two spal fans each connected to a standard bosch relay and each with their own 30 amp fuses. Both fan relay ground wires are then connected to the GM Oranage and black wire on the PCM that contols the low speed fan. The fans draw 18 and 14 amps respectively hence the two relays and fuses but want them both to run together so that is why they are connected to the one wire.
Your suggestions makes sense. That said why can't the PCM run my fans? I understand taking an on off signal based on a sensor from the rad would work but am I not able to have this pcm understand to turn on and off like factory?
I will look into your suggestion but am very new to this and not sure what to buy. Likely best to call them directly.
Do you know your circuit?
My advice is to set the tune up for no E-fans, and use
thermostats (see Digi-Key.com) epoxied to the radiator
to run fan relays high and low. The stock scheme is just
stupid. Your fans should be maintaining radiator core
temp, not head temp (that is the thermostat's job, the
radiator core needs to stay well below setpoint so you
have some authority and reserve).
First off thank you for responding and trying to help. The wiring in place sees two spal fans each connected to a standard bosch relay and each with their own 30 amp fuses. Both fan relay ground wires are then connected to the GM Oranage and black wire on the PCM that contols the low speed fan. The fans draw 18 and 14 amps respectively hence the two relays and fuses but want them both to run together so that is why they are connected to the one wire.
Your suggestions makes sense. That said why can't the PCM run my fans? I understand taking an on off signal based on a sensor from the rad would work but am I not able to have this pcm understand to turn on and off like factory?
I will look into your suggestion but am very new to this and not sure what to buy. Likely best to call them directly.
04-18-2011, 10:11 AM
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Just here to close the loop on this thread in that it might help someone else. Seems the issue with fans was a setting on A/C pressure of the refrigerent. There are two codes that need to be set from 2 to 3. By doing this it tells the computer to ignore the AC system and not scramble the fans into the on position if everything is not perfect. By going to number 3 it tells the computer to ignore and mis signals from AC and return to the normal programing of the fans.
Fans worked perfectly once I made this change.
Cheers.
Fans worked perfectly once I made this change.
Cheers.
04-27-2011, 11:48 AM
#5
I wonder why that worked...and it it's truly 'perfect'. Keep in mind that the factory fans actually has three relays...not two. The low speed is controlled by engaging the low speed relay. This runs power from one fan, out of that fan to the positive side of the 2nd fan, then to ground. This way the fans are in series and you get the low speed. By engaging high speed, the PCM engages the other two relays. This gives each fan it's own individual ground circuit and puts the fans in parallel. I suspect you don't have the factory intended operation of the fan...even though it may do exactly what you are after. Low speed is attained by wiring in series...not a different voltage supply or PWM.
