Relays or Switches with Breakers
 

My Son-in-Law and I are to the point of creating / modifying the electrical harness for his '86 Foxbody Mustang. It is to be a streetable drag car.

For all of the electronics (fans, ignition, start [well that will have a relay], pumps, lights, turn signals, nitrous run and purge):

Pros and Cons, with opinions between
1) running full current switches with circuit breakers to each of the above vs
2) running fused relays to each circuit with control-only current to the switch panel.

If we were to run with relays, should we put in 1 panel for all the front stuff, and 1 panel for all the rear stuff?

Relays for everything with circuit breakers.

Or use a digital power management system.

https://www.miataturbo.net/attachmen...ine=1409947530

http://www.motec.com/image_display.p...DM+diagram.png

https://www.miataturbo.net/attachmen...ine=1409947530

http://www.motec.com/image_display.p...568_keypad.gif

https://www.miataturbo.net/attachmen...1&d=1409947487
(photo courtesy of 949 Racing)



MoTeC > About Power Distribution > Overview

Joe, I'm gonna say that is some nice stuff, but a bit out of his price range. I'm sure he'll love the pic, though. Very well done. I suppose this is "Crusher"?

DNM

'Tis Crusher. And while I wish I could take credit, all I did on that car was some of the ECU work- the basics of the power system were all done before I got my hands on it.

And understood about the price. I guess at the rate that car probably eats transmissions, there's not a lot of money left over.

(bazinga.)


Switches vs. Relays... The OEMs like relays because it allows them to design small switches with a very light feel, and minimize the amount of heavy-gauge wire that has to be run.

Personally, I'm a big fan of simplicity. If there aren't a lot of circuits that need to be controlled, and the budget does not allow for anything more complex, I'd personally elect to just run full-current toggle switches and an off-the-shelf fusebox / distribution panel. I see no advantage to adding extra complexity and wiring by inserting relays in the middle of everything.

System Purchased, not yet installed
 

He went with a relay system by Race Wire Solutions, that was custom set up for his needs. I think he put more $$ into it than I thought he would.

https://www.miataturbo.net/attachmen...1&d=1422136450
System, not installed

https://www.miataturbo.net/attachmen...1&d=1422136450
Close-up of relay bank

https://www.miataturbo.net/attachmen...1&d=1422136450
Remote switches mounted to top of roll cage for easy reach.