I found the one fan on the '7730 but the $8D code shows the ability to turn on and off TWO (2) fans at different temperatures. Where can I get the wiring for the second fan?

I found the one fan on the connector E8 (grn/yel wire).

Anyone know where the "2nd" fan wiring is located?

Thank you in advance.

 

Are there two fans available in the '7730?

 

This is what I did, it works great.
jump a wire from pin F8 directly to pin D12

Read this thread about 2nd fan control by the ECM.(https://www.thirdgen.org/techbb2/sho...nd+fan+control)

Post from thread above:
I think I am going to jump a wire from pin F8 directly to pin D12. Instead of moving pin D12 to F8. That way the ECM will know when the second fan is been turned on by the A/C cooling fan pressure switch via the “Fan request signal”, pin D12. I will leave the factory secondary cooling fan temperature switch and wiring to act as a backup.

For a master override, I will hook a switch up to D12 to allow me to turn on both fans manually.

I have read the total fan control article also but I rather not spend any money on aftermarket parts when I can do it for free and have more control.

Here is a fan control schematic of the 90-92 camaro with a 730 if anyone wants to see the stock wiring setup: ftp://ftp.diy-efi.org/pub/gmecm/man...7730v8tpi-4.jpg

 

Thanks for the reply, and the search.

That seems strange...

I don't have an automatic. But I do have two fans.

Currently, I have both fans on a seperate circuit/probe and two relays. This probe setup from Haldane (I think) is measuring temperature of my radiator. It turns on around 190, and off aroud 185 (or less).

I am running a 180 degree thermostat. I also have a custom five row radiator. I hate overheating. These two fans don't seem to be doing a very good job in the 100 degree heat. While it's not overheating (head probe shows 200 degrees) while the computer has not shown over 190 degrees.

But I am still afraid of overheating. Perhaps I should go back to my OEM clutch-type fan on the waterpump... I really don't want to though, especially if I can control the fans better.

When would the D22 (second) fan turn on? How would it be controlled based on engine temperature, where is this in the code? Or more importantly where is it in the $8D?

I am so confused... in this diagram
http://www.eecis.udel.edu/~davis/z28...730v8tpi-4.jpg
I see the fan is on GE8??? What is this?
D12?

I thought there was only A,B C,D and E,F row connectors? What is GE8?


Darn, I am so confused...

 

OK, I htink I have this,

E8 is the primary fan - right?

F8 is the secondary fan - RIGHT?

D12 is the secondary fan letting the computer know that the second fan is on... right?

Thanks.

 

This is how I have my fans controlled (using the aujp bin)and it works great.

https://www.thirdgen.org/techbb2/sho...hreadid=231080