Fan wiring schematic holley terminator x

[MAGONSTERZ68]

Does this fly?
or should i just wire up traditionally, running positive through relay?

[dontlifttoshift]

That works but I can't think of a good reason to do it that way.

[dhutton]

I would run a pwm controller. That is going to be noisy….

Don

[MAGONSTERZ68]

That works but I can't think of a good reason to do it that way.

I was thinking it wouldn't starve the fans for power if drawing directly from power producing source when car is running.

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I would run a pwm controller. That is going to be noisy….

Don

can i run a PWM with regular SPAL fans about 4yrs old, do they need to be compatible?
using neg tirgger from holley terminator x pcm

[MAGONSTERZ68]

I would run a pwm controller. That is going to be noisy….

Don

if PWM is not compatible could i run them in parallel with a 3rd relay for low/high or do fans need to be compatible as well?

[Hotwire]

I would recommend series/parallel as mentioned earlier. On low you won't even be able to hear the fans over the engine just like on a stock setup. The fans don't have to be matched pairs / made on the same week / or be "calibrated" to be wired in this fashion. There's no risk of fire or malfunction as long as you don't have 2 completely mismatched loads wired together like a tiny transmission cooler fan and a large current hungry rad fan. As long as they're the same size, you will have 0 problems.

This is a video I made of my setup. 00 Camaro fans wired up with a 3 relay combo exactly like they did from the factory. On low the fans are in series sharing 12 volts, so each is seeing 6 volts while running. On high the relays switch them to parallel so both fans see all the battery voltage/current they could ask for. It's a great setup.

https://drive.google.com/file/d/13WU...usp=share_link

[MAGONSTERZ68]

I would recommend series/parallel as mentioned earlier. On low you won't even be able to hear the fans over the engine just like on a stock setup. The fans don't have to be matched pairs / made on the same week / or be "calibrated" to be wired in this fashion. There's no risk of fire or malfunction as long as you don't have 2 completely mismatched loads wired together like a tiny transmission cooler fan and a large current hungry rad fan. As long as they're the same size, you will have 0 problems.

This is a video I made of my setup. 00 Camaro fans wired up with a 3 relay combo exactly like they did from the factory. On low the fans are in series sharing 12 volts, so each is seeing 6 volts while running. On high the relays switch them to parallel so both fans see all the battery voltage/current they could ask for. It's a great setup.

https://drive.google.com/file/d/13WU...usp=share_link

xcllnt, will look up a wire up diagram tonight unless you got one handy, thx again.

So here is what i found, look right for a series wired parallel dual fan set up, but do i just tap the V/Air trinary grounding switch wire to the second fan ground signal out from terminator x?

Attachment 203959

[Hotwire]

xcllnt, will look up a wire up diagram tonight unless you got one handy, thx again.

So here is what i found, look right for a series wired parallel dual fan set up, but do i just tap the V/Air trinary grounding switch wire to the second fan ground signal out from terminator x?

Attachment 203959

Unfortunately all three relays need to "on" to switch to parallel config. You could run a diode between the trinary and low side to keep the low from triggering the high side when not using AC. Something cheap like a 1N4007 would be fine. I used to run these when putting electric fans on cars w/ mechanical fans. The diode would go between the a/c clutch wire and the fan's thermostat. When the a/c clutch came on it would trigger the fan also, but if the a/c was off the thermostat would not trigger the a/c clutch.

If you're unfamiliar, a diode is like a one way sign for current. It will allow it to flow one way but will block it the other. With the diode in place it will allow the trinary switch to operate the low side relay but will not allow the low side signal to operate the high side.

[MAGONSTERZ68]

Unfortunately all three relays need to "on" to switch to parallel config. You could run a diode between the trinary and low side to keep the low from triggering the high side when not using AC. Something cheap like a 1N4007 would be fine. I used to run these when putting electric fans on cars w/ mechanical fans. The diode would go between the a/c clutch wire and the fan's thermostat. When the a/c clutch came on it would trigger the fan also, but if the a/c was off the thermostat would not trigger the a/c clutch.

If you're unfamiliar, a diode is like a one way sign for current. It will allow it to flow one way but will block it the other. With the diode in place it will allow the trinary switch to operate the low side relay but will not allow the low side signal to operate the high side.

Not a problem running a diode used before when installing new vintage gauges to prevent unwanted feedback, will place between trinary an second fan relay negative trigger.
Am ok with high/second fan trigger only turning on one fan on high when ac kicks on as it is controlled by Vintage air head unit and usually if its hot enough for a/c here then odds are trigger one is already engaged turning on both fans on high which makes for lower a/c head pressure.
Thanks for the 411

[Sinnister69]

I have a spal brushless fan with built in pwm. I run it to a breaker then let the term x control it

[MAGONSTERZ68]

at the cost of replacing two 11" spal fans, may be in best financial interest to wire in the 3 relays already in my possession but good to know, thx