When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
So here is the deal.... It's pretty simple TBH (71yellow454's diagram pretty much lays it out) but there are about a 100 different ways you can go about it but there is some prerequisite information you have to know regardless of how you do it.
1. What is the startup and the running amperage for either the assembly or the single fans. You want to size your fuses and relays accordingly.
2. What kinda shape is the charging system like on your car? Is everything OE 1968? If so you must add an auxiliary fuse block (or at a minimum weather rated fuse holders) to the car and also upgrade the alternator. The Aux fuse panel needs to be at worst connected to the main battery lug on the starter. A direct connection to the battery would be preferred, but you could run it in tandem off the starter lug. You must ensure the fans pull their power from the Aux fuses and not through the OE harness. Not ensuring this could result in a fire given the OE harness is only rated for 30-40 amps and the pair of fans is likely to pull this on their own.
The 100 ways you can do it.
You can purchase a programmable controller similar to this. Some of these kits use a radiator probe, some use an in the block sender. Pros and cons to both. I am in no way endorsing this particular unit, this is just an example of what's out there in the market of. Of these some are wired for AC compatibility some aren't. When you know your fan specs you can check the ratings against said kit. Purchase accordingly.
You can purchase a static controller similar to this. Some of these kits use a radiator probe, some use an in the block sender. Pros and cons to both. This particular one uses an OE style switch off a mid 80s Camaro. Again I am in no way endorsing this particular unit, this is just an example of what's out there in the market. Of these some are wired for AC compatibility some aren't. When you know your fan specs you can check the ratings against said kit. Purchase accordingly.
You could use a manual fan kit similar to this . No way would I ever run something like this on a street vehicle but it is an option.
You can wire up your own solution using whatever parts and pieces of your choosing that are appropriate for the given load. Given you're asking I'm inclined to believe you wouldn't want to piece together your own solution. Thus I would recommend you pickup a kit with all the necessary wires and relays
I bought this wiring kit but use a different temp switch for my 180 thermostat. (actually I have multiple wiring kits and plan to use 2 relays.. But this has the correct spal type wiring plugs for the fans. https://www.ebay.com/itm/185-165-The...72.m2749.l2649
These fans draw 30amps for startup and 15 amps continuous.. I believe that might be for each fan though, I cant remember for sure.
You can go to the dewitts page and see he recommends a larger alternator but states a stock should work... dont forget you do have a battery for reserve and unless you plan on spending a lot of time sitting in traffic realistically it should be ok. some will say you need a 144 amp alternator though. Also here Ive read multiple times the 6awg wiring kits are only good for 80a even though since the load is not continuous they are good for up to 140A setups elsewhere. I intend to use my 105A 10-12SI universal I installed a couple years ago. I did buy the painless wiring upgrade to beef things up but I have a stereo with an amp as well. I upgraded to led lights which draw less current than the original lights.
Last edited by augiedoggy; Jan 24, 2021 at 09:33 PM.
I like using a PWM controller - and the Blue Sea Marine fuses
1. Has soft start- doesn't go full boogie on your battery/charging system as it slowly starts the fans up
2. It varies the speed of the fans as needed- not on- off- on...
3. Own temp sensor to control then fans
4. Has a over ride switch- turn on the fans full speed with the flick of a switch ( AC)
5. Made in USA!!!
Buying the spal wiring harness makes it easy, I ran mine that way for a bit then went to two different temp sensor and let it run on a single fan unless it needed more. Two years ago went to a PWM controller with soft start and it's been excellent as well
M
Yup, that's the controller Richard posted I'm running now, a lot of people seem to have problems with them but I think you just need to be careful wiring and there's no issued (once they sent the "new" style temp sensor for aluminum rads)
I like using a PWM controller - and the Blue Sea Marine fuses
1. Has soft start- doesn't go full boogie on your battery/charging system as it slowly starts the fans up
2. It varies the speed of the fans as needed- not on- off- on...
3. Own temp sensor to control then fans
4. Has a over ride switch- turn on the fans full speed with the flick of a switch ( AC)
5. Made in USA!!!
That's pretty kickass. Didn't know this kinda fella was out there. I've been doing it with a dual temp BMW switch with relays for ages. Gotta look into this more.
Here's the way I did mine. When ignition is on they run at low speed and when temp gets high they switch to high speed. I have EFI that does the switch to high but you can use a temp sensor or even a simple toggle switch.
Dual electric fan wiring
