On my GN I used a on/off toggle at the ALDL connector. I use this to cool the car down at the track and turn it on when in traffic with the A/C on. The also uses the timer on the relay that shuts off in 5-10 min.

Does my 92 Z28 have this same feature?

 

During the code retrieval process the ECM will turn on the cooling fan as a self test.

 

i would rather have a manual switch inline with the stock fan switch or cts. i dont think u are suppose to have the car turned on and be in the code retrival mode, so a manual switch like that wouldnt be a good idea but i might be wrong. at least thats what i heard when using the thirdgenners scan tool (a paperclip)

 

A ground switch is so easy to wire, I wouldn't take the chance of something happening from the "paperclip" trick.

 

Is just relays controlling the dual fans? Or its a module with timer and relays?

 

Opps my bad.....I was thinking now I did not tap a wire at the ALDL connector to turn on the fans. It was to lock-up the TC.

I use a wire at the relay module for the stock fan and use a switch to ground a wire to the relay, making the fan run on low speed and also when the car is shut off the timer kicks in and the fan stays on for 5-10 min.

I did a search and found nothing like my GN but have to wire up another relay in between to have these fans come on earlier or have both fans on the same time. Is there something like replacing the factory relays to make it come on at high when the engine is at a lower temp.

A few time while driving in traffic I had to shut the A/C off to keep it going to 220 degrees!