Dual cooling fans - how many relays?

[Promise Land]

I have the dual Isis cooling fans and am running one fan with one relay. If I run the second fan, do I need a second relay? What is everyone else running?

[HIGHFIVEBETA]

1 Bosch style 30 amp 5 pin. Good enough for me.

[N2HIFI]

1 relay is fine just make sure your running proper gauge wiring (12-10g) and fused properly

[orion::S14]

I wouldn't chance it with one relay.

It's WAY too easy to split the load, and ensure some reliability.

I run 4 total - Altima fans - 2 fans, with high and low each. I use the OEM S14 setup (2 relays, one for high, one for low) to run one, and added two new relays to the system for the 2nd fan.

Overkill, yes...but it's not gonna melt the harness and cost me a headgasket on some summer day.

- Brian

[godrifttoday]

I would use 2 relays 1 switch to control both fans.but u might be able to get away with one if u know how many amps the fans pull to use a standard 30 amp relay

[myfuzzybutt]

I have the dual Isis cooling fans and am running one fan with one relay. If I run the second fan, do I need a second relay? What is everyone else running?

dif 10090 - Google Search (http://www.google.com/search?q=dif+10090&hl=en&rlz=&gs_sm=e&gs_upl=315l6919l0l7326l22l20l0l11l0l0l217l1336l2.6 .1l9l0&um=1&tbm=isch&source=og&sa=N&tab=wi&oq=dif+100&aq=0S&aqi=g-S1g-mS1&aql=)

And it looks good under boost controllers and DEFI gauge brains!!! Worth every penny.

[S-Nation S13]

I use 2 relays 2 fuses ...one runs constant other on a switch

[Kiro1968]

Best to run 1 relay for each fan at least. I would not chance it with just 1 relay for 2 fans. You can run a resistor on one of the fans for a low speed run.

Just a thought ^_^

[Croustibat]

Best to run 1 relay for each fan at least. I would not chance it with just 1 relay for 2 fans. You can run a resistor on one of the fans for a low speed run.

Just a thought ^_^


what a great idea ... hope he does not use standard 1/4W resistor for that or hes going to have fire in his engine bay ...

1 relay for 2 fans is enough, just make sure it is a 30 amp one.

[GSXRJJordan]

Quick answer is, it depends on the fan.

Most ebay/cheap fans only draw 12A or so once they're started, but 'inrush' current (the current drawn to get the fans up to speed) is going to be 20A+. The Bosch Motorsport fans we sell are 30A ea continuous, with an inrush current of about 100A lol. Turning them both on at the same time will kill a cam'd 4cyl at idle haha.

A slow-blow fuse or a single 30A push-to-reset breaker like we use would work fine with a decent 30A/40A relay and 12ga/10ga wiring from the power source to the fuse, fuse to breaker, and at least 16ga to each fan out of the relay.

Make sure your grounds are either very short or just as big as the power wire, and grounding to a clean grounding location on the frame.

[GroundPerformance]

I will be running Altima Fans on my current project. This is how I will be wiring it on my S13 Non-AC Coupe.

https://fbcdn-sphotos-a.akamaihd.net/hphotos-ak-ash4/394913_3096613780341_1413997181_33183325_128041074 6_n.jpg

[S-Nation S13]

I will be running Altima Fans on my current project. This is how I will be wiring it on my S13 Non-AC Coupe.

https://fbcdn-sphotos-a.akamaihd.net/hphotos-ak-ash4/394913_3096613780341_1413997181_33183325_128041074 6_n.jpg

Care to share the where abouts of you thermo switch????? I have the exact setup but since I went ghetto I have one running on constant and the other on a switch ..

[GroundPerformance]

Painless, Summit and others sells the kit with the relay, switch and others for around 40~60. I will be putting mine together to save some $$ and only got the switch by itself. I found it on eBay for a little over 20 shipped just search for "185 Degree Electric Fan Thermostat Temperature Switch"

[r33nota240]

u would be safe with one if u ran ur fans on ground trigger meaning put ur relay to cut ground.