i apologize if this is the wrong place to post this...

1. on ANY of th yrs with tpi and dual fans, can both of the fans' turn on/ off temps be controlled by the computer? iirc, the first fan is controlled by the computer, and the second by the temp switch. if i'm wrong, could be the lack of sleep. oh yeah, and the ac turning on controls one. the reason i'm inquiring is because i had a chip tuner tell me that he could set both fans' parameters in my computer?

2. if the above is true, are the fan switches still necessary?

thanks in advance.

 

Both can be controlled by the computer....look for a post by Glenn91L98GTA where he tells you how(search is down or I would have linked you to it). There is some rewiring of the ecm connector involved tho..nothing major just swaping some wires.
No the fan switch is not required but I would leave it in as a backup just in case.

 

my brother has an 88 with dual fans,
his ecm only can control 1 fan the other is controled by a temp switch,

my 89 only has a single fan controlled by the ecm,

90+ that I have done work on have dual fans both controlled by the ecm

 

this may be helpful

https://www.thirdgen.org/forums/diy-prom/182538-second-cooling-fan-control.html

 

thanks 91L. appreciate the link since search is down.