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I found a set of LS1 fans I'd like to put in my 89 Firebird 2.8. The LS1 fans cover more of the radiator etc... and they work excellent in my V-8
Im planning to just plug in one fan to the stock wiring and make a separate relay / power for the second fan, but want it to come on when the stock fan comes on (a/c and cooling).
I was looking for a trigger wire, but then from my understanding found that the V6 cars work by grounding the circuit
My question is, does anybody know how to ground out the second fan to make it come on when the main fan comes on? Im not sure where / how the grounding works on these. Or if there's a better way to tap into the fan wiring.
If you looking for it to work in tandem with the original fan, you can connect relay #2's coil in parallel with the original relay's coil, and both relays will activate at the same time. What I would not do, however, is that I would not hook the second relay's switched contact to the same power feed as the first one (the fusible link "J rust" shown at the bottom of this schematic). I would run that second fan's relay switch power from a fuse or fusible link of it's own connected to the battery, perhaps by means of the big terminal on the starter or a terminal block connected to the battery's positive wire. I say this because on your V6 where there never was an option for dual fans, the fusible link likely isn't sized properly to feed two fans VS one.
If you looking for it to work in tandem with the original fan, you can connect relay #2's coil in parallel with the original relay's coil, and both relays will activate at the same time. What I would not do, however, is that I would not hook the second relay's switched contact to the same power feed as the first one (the fusible link "J rust" shown at the bottom of this schematic). I would run that second fan's relay switch power from a fuse or fusible link of it's own connected to the battery, perhaps by means of the big terminal on the starter or a terminal block connected to the battery's positive wire. I say this because on your V6 where there never was an option for dual fans, the fusible link likely isn't sized properly to feed two fans VS one.
Ok thx! my plan is to wire it totally separate, like from a fuse block I installed before with relay etc..
I was looking at this diagram last night...….If I splice the second relay ground to the green / white wire closer to the original relay by the fire wall, do you know if this ground activates the fan for both cooling and for ac?
Basically, if I splice the second relays ground into this green / white wire that goes into D2, will that turn my secondary fan on / off with the stock fan?
Last edited by 1989karr; Aug 24, 2021 at 02:02 PM.
Yes it will. One side of the relay's coil gets +12V anytime the key is on (brown wire) and the other side of the relay's coil (dark green/white wire) gets switched to ground to activate the relay. If you give one side of your new relay's coil +12V with the key on and connect the other side of your new relay's coil to the dark green/white wire, both relays will activate when the dark green/white wire gets grounded. Of note is the fact that the schematic is incomplete, it only shows the ECM connection to the relay's coil when in actual practice there is the temperature switch screwed into the cylinder head connected to the dark green/white wire as well as a connection to the HVAC control as well.
I was looking at the car thinking I needed to directly splice into both the HVAC wiring and the fan switch in the head as I couldn't figure the wiring, and the Haynes book doesn't show the wiring once it goes to the D2 connector.....
This info will make things a lot easier! thank you!!
Hard part will be making everything fit physically now!
I was looking at the car thinking I needed to directly splice into both the HVAC wiring and the fan switch in the head as I couldn't figure the wiring, and the Haynes book doesn't show the wiring once it goes to the D2 connector.....
This info will make things a lot easier! thank you!!
Hard part will be making everything fit physically now!
Very good, just remember to properly fuse your new relay's switched power source and you'll be fine.....
Your welcome, and if you have any more questions I'll be happy to help....
ok, i did a test wiring...wired up a relay as i would a "real " one just not wired nicely, grounded to that relay green / white wire...and it works! works beautifully with ac and from temp...cools sooo fast.
ok, i did a test wiring...wired up a relay as i would a "real " one just not wired nicely, grounded to that relay green / white wire...and it works! works beautifully with ac and from temp...cools sooo fast.
thank you!
Awesome, now all ya gotta do is make it pretty, I'm happy to hear of your success with it
I realize I also happen to have a 3.1 rad which is the same as a V8 car i think. the 2.8 is smaller
Fun project! I think the LS1 fans might clear the ac lines a little more since they are slightly slimmer. Lt1 are slightly thicker but the fans are removeable from the shroud which makes things easi as well.
It can probably be done for cheaper etc.. like if you make your own air intake out of PCV etc... .... but if people can do it I recommend it!
