E-fans tunning problem

[ltdakheel]

hi guys
i have 2004 GMC safari i installed E-fans using the 2004 savana harness GM 15912597 all pining and connector are okay ,,the fans are running low speed and high speed for ECT , but when A/C is ON they runs at low speed all the time until the pressure gets high then COMP disengage , any idea why ,
??

[Shrek]

Couple of things ... Express / Savana never used electric cooling fans ... your wiring harness segment was used in 2005 to 2007 (classic) light duty trucks / SUVs. It is only a segment of the totality of the wiring harness.

GM used ECT to trigger E-Fan activation - which it seems you have working properly. With respect to A/C - GM used A/C pressure to trigger E-Fan activation. This requires the use of an A/C pressure sensor - which you will need to add to your Safari's A/C system - if you want the E-Fans to operate based on A/C activation (pressure). Your Safari's A/C system would have originally used Low & High pressure switches - but no pressure sensor.

[ltdakheel]

thank you shrek , on same car i used pcmforless harness and it was working fine wiht both A/c and ECT but high speed only , and this harness used on 05 and 06 silvarado,s , 2007 up pcm doesnt have fan 1 and fan 2 setting , its just percentage of speed VS ECT i will dig more and try deffrent setting and thank you for heads up

[ltdakheel]

http://www.gmtruckclub.com/forum/sho...#axzz2Bl62vCEj

this where i get the inspiration o do my efans

[Shrek]

... this harness used on 05 and 06 silvarado,s , 2007 up pcm doesnt have fan 1 and fan 2 setting , its just percentage of speed VS ECT ...

2007 (Classic) are the same ... 2007 E38 are different.

... i will dig more and try deffrent setting and thank you for heads up ...

Will never work right without adding an A/C pressure sensor ...

[ltdakheel]

i can see your point man , just came to my mind that savana 04 comes with A/c pressure sensor because the have electric fan clutch ,and thats why savana guy didnt have any issue with his setup
http://www.gmtruckclub.com/forum/sho...0-Savana-Cargo

is there any way i can add that sensor to my van , can you help me please

[ltdakheel]

i added the sensor connector C2 pin 14 A/C Refrigerant Pressure Sensor Signal and still no result , sorry shrek your idea is not good

[Shrek]

It is not my idea (I wish it were - I would be a wealthy person), it is how GM controls the E-Fans in Gen III trucks. You need to use an A/C Pressure Sensor compatible for use in a 2003 - 2006 Escalade / Tahoe / light duty truck/ etc. The A/C Pressure Sensor connects to the PCM in 3 places:

• C1 (Blue) pin 45 - is the 5 volt reference
• C1 pin 80 - is the ground
• C2 (Green) pin 14 - is the signal from the sensor

The A/C Pressure Sensor must be installed in the high pressure side of the system. The A/C type in the PCM must be changed according - for proper function.

This is becoming more of a "how to" swap thread, rather than a tuning thread.

[ltdakheel]

i will give i try tommorrow man , and the sensor installed (wilded on the high side ) i,m using 3 wire style sensor came on 2004 tahao , i can run it with pcmforless harness like before and have high speed only , my head is locked to get low speed , here the weather in summer is like 127 F durring the day and 115 night , with clutch fan its very very noisy , i will updated soon inshala and then will move it to how to side

thanks again for the reply

[ltdakheel]

hi shrek , thank for the pining , now i can see A/C pressure on hp tuners scanner ,do you know where C2 18 DK GRN 59 A/C Compressor Clutch Supply Voltag must be connected and pined this in case i need it , and where i can find A/C type in the PCM that must be change for proper function. because still no high speed for the A/c , from VCM control when i turn high speed fan on while AC running both fans go high speed :0

It is not my idea (I wish it were - I would be a wealthy person), it is how GM controls the E-Fans in Gen III trucks. You need to use an A/C Pressure Sensor compatible for use in a 2003 - 2006 Escalade / Tahoe / light duty truck/ etc. The A/C Pressure Sensor connects to the PCM in 3 places:

• C1 (Blue) pin 45 - is the 5 volt reference
• C1 pin 80 - is the ground
• C2 (Green) pin 14 - is the signal from the sensor

The A/C Pressure Sensor must be installed in the high pressure side of the system. The A/C type in the PCM must be changed according - for proper function.

This is becoming more of a "how to" swap thread, rather than a tuning thread.

[ltdakheel]

common man do leave now