1994 Z-28

I'm trying to determine which cooling fans come on when.

I did some testing and here's what i got:
Outdoor Temp 85
All done at idol.

Initial start up, no fans running.
When temp reaches about 210, Fan 1 comes on. Turns off around 170.
Turn A/C on, Fan 1 comes on.
The only time I have noticed Fan 2 come on is if the MAF sensor is unplugged when running, then both fans come on.

Is Fan 2 supposed to come on when the A/C is turned on as well as Fan 1? I would think so as this would help the AC to run cooler.

Let me know please.

 

could be the relay is failing. try changing with a known working one. all the relays are the same except the abs one. first fan is set to come on at 223, second should come on at 235.

 

i did swap the relays and FAN 1 worked fine. I guess it just hasnt made it to the temp to turn on FAN 2. I guess I could pull the relay from FAN 1 and see what happens. Thanks

 

yep it may be that your cooling system is workng well enough that it rarely turns the second one on. thats a good thing.

 

fyi i have a 180 degree thermostat in mine and had it tuned for the 180. it hangs between 180 and 200.

 

Me too, ( 180 stat ) however, I removed the airpump, EGR, cat, had it programmed for this setup, changed every sensor and both fans come on as some as its a little warm and never go off. Thought I might throw that one in there for you craby if you dont mind helping both of us at the same time. Thanks ! Seems like I remember something about having this problem after removing the airpump.

 

tap into the high and low speed wires coming from the pcm that way you will only working with ground and no power check check shobox's website for more info

 

Ok, I found the 2 wires for the 2 fan relays and grounded them to test and they worked. I guess if i had looked one line down on shobox from the Fan Schematic i would have seen it.

Now should I put both fans on 1 switch or 1 switch for each? I basically just want to keep the air flow going when in traffic during the summer months to help the AC out a bit. FAN 1 will already be running if the AC is on.

Will both fans running increase performance when the AC is not on?

Also, the way it is wired on the diagram, it looks like the LED's will light up when the switch is off and the PCM calls for the fans to come on. Am I correct?

 

jegs has a kit that u may be interested in. 69 bucks, turns fans on manually via switch yet retains stock fan operation...as they say in their write-up.
I did something similar to you you lazyguy...but with me i can turn the both fans on whenever via a switch... or the pcm will turn the fans as it should. it never does though cause i just flick the switch before hand. i removed the ac so i cant help ya there. one thing tho...it cost me bout 50$ for the wire, heatshrink, lil connectors, fuses n fuse holders plus the switch. 69 bucks was probably the way to go. btw mines a 93 z, different schematic i think.