Chase Bays Dual Fan Relay Wiring Harness with 180º F Thermoswitch


Chase Bays


Ships Direct from Manufacturer


A very common problem we ran into when selling Radiators was insufficient fan wiring. In many cases; powerful electrical fans are installed on chassis that came with mechanical fans. The factory A/C relay(s) that use smaller gauge wiring are tapped into and wire that cannot handle the high amperage is used to run to the fans themselves. If its not that, its that one relay is used to power two fans. Either way, the issue is half powered fans and a temperature gauge that keeps climbing. 

We wanted to make an all-in-one solution that was super easy to install and looked incredible. There are dozens of other fan relay wiring kit solutions but this stands far from the crowd. Other kits are two pre-crimped relays, some butt connectors, and a handful of zip-tied wire. Not cool. 

This Dual Fan Relay Wiring Kit is comprised of a small weatherproof Relay/Fuse Box with easy to adapt mounting bracket, fireproof sleeving as seen in our video (click here), yellow labels on each lead to eliminate the guesswork of whats what, and all TXL thin jacketing wire. 

The install couldn't be easier. The wires labeled "thermosw" run to the included 1/8 NPT thermo-switch that you will install on the post-thermostat lower side of your radiator. Any Chase Bays Tucked Radiator purchased from 2018-on will have (2) 1/8 NPT ports on the radiator. If you're installing this on another radiator all you need is an 1/8 NPT female weld-on which can be purchased by clicking here. The wires labeled "fans" go to your fans (duh!). Then you just ground the "GND" wire to a clean surface with steel or stainless steel non-painted bolt.

The wire labeled "battery" is the main power wire. It can be connected two different ways. It is already fused in the fusebox so it can be connected direction on the battery, alternator, or starter. If you do this, the fans will stay on until the coolant is below 180º F. Even after the car is turned off. If you don't want it to be this way, just hook the battery lead up to a switched 12v source. (Disclaimer: We're not sure where that is on your particular chassis and can't assist you in finding it)

The fan and fan relay power wires are all proper 14awg wire crimped with a certified Mil-Spec pneumatic crimper, all terminals are nickle-plated for 110% connections, and Deutsch connectors are used for the fans.

FAQ, Product Revisions, and Fun Facts

 YES this can be used for anything and everything, not just our tucked radiators. The only missing piece you may need is an 1/8 NPT female aluminum weld on bung. We sell those. CLICK HERE FOR A LINK. 

Always use LIQUID TEFLON SEALANT thread sealing compound to avoid leaks and to prevent galling of threads. Pipe tape can insulate the thermo-switch from creating a proper reading plus it can break off and go into your cooling system. 

Returns Policy

You may return most new, unopened items within 30 days of delivery for a full refund. We'll also pay the return shipping costs if the return is a result of our error (you received an incorrect or defective item, etc.).

You should expect to receive your refund within four weeks of giving your package to the return shipper, however, in many cases you will receive a refund more quickly. This time period includes the transit time for us to receive your return from the shipper (5 to 10 business days), the time it takes us to process your return once we receive it (3 to 5 business days), and the time it takes your bank to process our refund request (5 to 10 business days).

If you need to return an item, simply login to your account, view the order using the 'Complete Orders' link under the My Account menu and click the Return Item(s) button. We'll notify you via e-mail of your refund once we've received and processed the returned item.


We can ship to virtually any address in the world. Note that there are restrictions on some products, and some products cannot be shipped to international destinations.

When you place an order, we will estimate shipping and delivery dates for you based on the availability of your items and the shipping options you choose. Depending on the shipping provider you choose, shipping date estimates may appear on the shipping quotes page.

Please also note that the shipping rates for many items we sell are weight-based. The weight of any such item can be found on its detail page. To reflect the policies of the shipping companies we use, all weights will be rounded up to the next full pound.

Financing Options Available - Click Here for Details