Dual Electric Radiator Fans?

[Phill's Vette]

Hey ACE!

Been a while since I've posted, hope you all are good!

I am going to be installing an aluminum radiator with dual fans this week and need some electrical wiring knowledge.

Together they pull 35 - 40 amps which is much more than OEM wiring/fan. I also understand that if the wiring is not matched to the amp pull, I will lose CFM output from the fans - not to mention a possible "Audio Express $1 Wire Fire"....

Currently I running an after market fan through the stock wiring, except I have bi-passed the temperature switch with a switch to my glove box.

What I have read is I should use relay(s) activated switching to control the dual fans, but what about the wiring? Has anyone done this? Does anyone have a basic schematic for automotive relays?

History:

Owned my 82 for about 3 years and just cracked my third radiator; obviously a heat problem and have installed high-flow water pump/t-state, 2500 CFM aftermarket fan and water wetter, but still had temps in the upper 220 -250 with AC on in traffic. I use this Vette as a daily driver and simply turning off the AC when it is 110 outside is not an option, though that is exactly what I have been doing - sweating my arse off!

Anyway, I just cracked the 3rd OEM style radiator and have ordered an aluminum radiator with dual fans that pull more than 3000 CFM and will finally provide this 82 with the cooling performance needed!

Thanks!

[ChadC]

Currently I running an after market fan through the stock wiring, except I have bi-passed the temperature switch with a switch to my glove box.

What I have read is I should use relay(s) activated switching to control the dual fans, but what about the wiring? Has anyone done this? Does anyone have a basic schematic for automotive relays?

using spall fans my BB never got above 170* during 115* days.

I used my fans to come on via the Ign (keyed) switch. I liked that so before I activated the starter I could hear both fans operate. Kindo of like a mental "pre-flight" checklist. The fans ran when the engine was running and the 'warmup' was controled by the theromostat.

Ifyou can crimp a wire then you can use a relay.

all a relay is a water controling device. A small amount if electricty is given to post 85 (ie the ingnition). The juice is the command to OPEN THE FLOOD GATES!! and let the raw pure power of the car battery come through Post 87 and exit to post 30, there by traveling to the fans.

Once post 85 stops getting its small amount of + electrity the flood gates slam shut and post 30 no longer has raw pawer comming out if it.

Here is you need.

normal 12V 30A relay. If you can get a 12v40A go for it, but they are hard to find due to the special nature.

Post 87 Goes to a 30amp fuse, and then directley to the battery +.

Post 30 goes goes to the + of both fans.

Post 85 goes to the Ignition/keyed wire. You will have to find that one your self. It will be a + wire that only gets 'hot' when the key is in the RUN/IGN position.

Post 86 goes to a gound -. yes I said ground. any ground wil do.

Post 85a and post 87a if so equiped are not used.

good luck, take your time, and think about 'other' stuff when installing. Dont just focus on the +/- wiring. Think about, virbration, water, engine heat, ease of access, mounting place.

cheers

chad

[Phill's Vette]

Currently I running an after market fan through the stock wiring, except I have bi-passed the temperature switch with a switch to my glove box.

What I have read is I should use relay(s) activated switching to control the dual fans, but what about the wiring? Has anyone done this? Does anyone have a basic schematic for automotive relays?

using spall fans my BB never got above 170* during 115* days.

I used my fans to come on via the Ign (keyed) switch. I liked that so before I activated the starter I could hear both fans operate. Kindo of like a mental "pre-flight" checklist. The fans ran when the engine was running and the 'warmup' was controled by the theromostat.

Ifyou can crimp a wire then you can use a relay.

all a relay is a water controling device. A small amount if electricty is given to post 85 (ie the ingnition). The juice is the command to OPEN THE FLOOD GATES!! and let the raw pure power of the car battery come through Post 87 and exit to post 30, there by traveling to the fans.

Once post 85 stops getting its small amount of + electrity the flood gates slam shut and post 30 no longer has raw pawer comming out if it.

Here is you need.

normal 12V 30A relay. If you can get a 12v40A go for it, but they are hard to find due to the special nature.

Post 87 Goes to a 30amp fuse, and then directley to the battery +.

Post 30 goes goes to the + of both fans.

Post 85 goes to the Ignition/keyed wire. You will have to find that one your self. It will be a + wire that only gets 'hot' when the key is in the RUN/IGN position.

Post 86 goes to a gound -. yes I said ground. any ground wil do.

Post 85a and post 87a if so equiped are not used.

good luck, take your time, and think about 'other' stuff when installing. Dont just focus on the +/- wiring. Think about, virbration, water, engine heat, ease of access, mounting place.

cheers

chad

Chad,

Now this is exactly what I was looking for! I'll post when finished.

Thank you!

:thumbs

[MikeMc71]

I bought the dual fan kit from Dewitts. It comes with relays, PLENTY of wiring, fans, mounts, and everything you need to hook it up. It bolts right up to the original radiator.

I also had to upgrade to a 100 amp alternator, I run the fans, A/C, and electric fuel pump. Checker has them in chrome for about $100.

[Desertdawg]

but still had temps in the upper 220 -250 with AC on in traffic.

Don't sweat the temps to much Phill, our 82 ran in that range every year, only saw above 240 if I pushed it. And remember the computer needs to see above 190 to get out of warmup mode and run normal....