I have it setup after a fi to carb swap , i need to be educated, on to how to set up a toggle switch , because the dual fans have juice going on them, even the the dual intake leads one to ground one for hot wires its all new btw , wont turn on at all. in the mean time i took the hot lead and connected it to a keyed voltage line when i turn the key to accessories the fans stay on all the time. Need to know how to wire a toggle up that way im not burning out the fans . Thank you in advance.

Mike

 

Get an aftermarket adjustable controller for them - they aren't that expensive and are great - takes away the need for YOU to watch the temp guage (which never reads accurate anyway) and constantly turn on/off fans. They are easy to wire, probe the radiator for temp readings. I got one 4 years ago, and have never had any issues with it at all.

 

do you have a link for a dual fan adjustable setup, through jegs or summit or someone else?

 

This is the one I used, it's pricey at $100, but it's the best $100 I spent!

http://www.summitracing.com/parts/FLX-31165/

There are simpler models from different manufacturers with varying prices, depending on the bells and whistles - even your local autozone/advance carries a few on the shelf.

With the one above, both fans will come on at the same time. You could buy 2 cheaper models, and set each up for each fan, adjusting the temps at different settings. But if it were me, I'd just rig both fans into a single controller like that one above and have them both come on at same time.

 

If your car is highly modified Do NOT install this type of fan control. Since your starting from scratch be sure to install a fan switch that uses a BLOCK MOUNTED temp sensor.

I've got a radiator probe fan switch relay on my duel fan carb'd set-up. It would probably be fine if the car was mostly stock, but once I start melting rubber my 355 gets hot - fast. There is a CONSIDERABLE lag time in the radiator temp reaching block temps. (The gauge will read 230 and the Radiator will be at 190-200 for example.) In that senario you think " Well- I'll just turn down the fan setting a little so it will kick on sooner next time". The problem is that when driving under more NORMAL circumstances the fan will be kicking on way too early and the engein can't reach operating temp ! ( It took me a LONG time to get it set "right" to work under normal and abusive conditions ! )

The same thing is true in reverse. The fans will kick the engine temps down below optimum range - but the probe is still dealing with a hot radiator and will keep the fan running when engine temps are lower then the radiator. ( Guage reads 140 but relay still has fans running cause radiator probe is still 170 !! )

I'm using 1 aftermarket relay ( Haden, about $40 ) http://www.summitracing.com/search/?...HDA-3647&dds=1 for both fans and to be honest an easy answer to this would be to install 2 relays. But; the problem with a lack of instant response from the temp switch would remain. After using a radiator probe fan switch for over a decade; I suggest a block mounted fan switch to everyone.

 

The following provides zero info about a toggle switch (I chose to not go that route because I'm an idiot who'd no doubt forget to the flip the fans on), but you might find the idea intriguing:

https://www.thirdgen.org/forums/cool...electrics.html

JamesC

 

Totally understandable logic. But, the fan controller I linked to kinda solves the issue with a bit of common sense. It has provisions for a toggle, so you ca turn the fans on anytime you like (like when you know your hotter than the guage). And it's fully adjustable - 10 seconds with a small screwdriver and set it anywhere you need (lower for the track, higher for the street).

But I see where you are coming from. And I also know several folks with 10 second cars using the same kinda rad probing controllers with no issues - like everything else you just have to know your car and operate it accordingly.

I just persoanlly never liked the block mounted jobs - I spent months and several hundred dollars trying to get them to work properly, everything from autozone junk to NAPA parts (better) to aftermarket high dollar (I spent over $100 on one brand) - and none of them worked longer than 45 days. And this was on a stock TBI car

 

The Haden switch also has a toggle. It's recomended that it's installed on the AC circuit so if you push the AC button - the fans kick on. Rather than splicing it to the AC wire it could easily be wired to a simple ON/OFF toggle. It too is also fully adjustable, just turn the screw.

Installing it on a 10 second car and having it work isn't a problem,..... take that 10 second car around town however and you will quickly see that the fans kick on WAY too early.

The best ( cheap ) solution is to cut the fan relay from an 84-87 Carbed car, buy a hypertech block mounted sensor ( PN 4026), & splice it together. On @ 176°F/Off @ 166°F,......... No toggle to forget - no adjustments based on how your driving the car that day. Total cost would be about $50 and a couple hours of effort.

P.S. Nice looking setup James !

 

That would be great if the Hypertech switch worked for longer than 45 days - I went through 2 of them in 90 days on a stock TBI car and finally gave up - that's when I installed the seperate controller and never looked back. But to each his own - I've just had too many issues with the head mounted switches and I won't go back when my seperate controller works so well and has for 4+ years now.