fan control...A/C pressure switch..two fans
#1
Supreme Member
Thread Starter
Join Date: Jan 2002
Location: California
Posts: 1,162
Likes: 0
Received 1 Like
on
1 Post
Car: Z28
Engine: L98
Transmission: T56
fan control...A/C pressure switch..two fans
does anyone have a copy of a page from a service manual for a car which uses '730 which has two computer controlled fans?
based on the information here I jumped BD12 to F8, which puts the ECM's fan2 output on the same line as the block coolant temp switch and A/C overpressure switch. Which means that whenever the ECM grounds fan2 (to turn it on based on my temp settings), it's going to see an A/C overpressure signal as well. the logic this invokes in the code (around LD362 in ANHT hac) is such that IF you turn the AC on, and IF fan2 gets turned on (for any reason), the ECM logic is going to latch fan1 on until the AC is turned off, and fan2 is going to get latched on unless VSS indicates a speed higher than the fan2 allowable speed w/ AC on.
I'd like to see how a two-fan 730 application is wired to see if there is a way around this, or if the logic in the code is different (presumably a non-$8D mask)
based on the information here I jumped BD12 to F8, which puts the ECM's fan2 output on the same line as the block coolant temp switch and A/C overpressure switch. Which means that whenever the ECM grounds fan2 (to turn it on based on my temp settings), it's going to see an A/C overpressure signal as well. the logic this invokes in the code (around LD362 in ANHT hac) is such that IF you turn the AC on, and IF fan2 gets turned on (for any reason), the ECM logic is going to latch fan1 on until the AC is turned off, and fan2 is going to get latched on unless VSS indicates a speed higher than the fan2 allowable speed w/ AC on.
I'd like to see how a two-fan 730 application is wired to see if there is a way around this, or if the logic in the code is different (presumably a non-$8D mask)
Thread
Thread Starter
Forum
Replies
Last Post
IROCZDAVE (88-L98)
Engine/Drivetrain/Suspension Parts for Sale
0
09-02-2015 08:49 AM
IROCZDAVE (88-L98)
Engine/Drivetrain/Suspension Parts for Sale
0
09-02-2015 08:43 AM