Relays or Switches with Breakers
#1
Retired Mech Design Engr
![](/mt2011/images_td/ranks/supporter1.gif)
Thread Starter
iTrader: (3)
Join Date: Jan 2013
Location: Seneca, SC
Posts: 5,010
Total Cats: 857
![Default](https://www.miataturbo.net/images/icons/icon1.gif)
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?
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?
#5
I identify as a bear.
![](/mt2011/images_td/ranks/supporter1.gif)
![](/mt2011/images_td/ranks/smod.png)
iTrader: (8)
Join Date: Sep 2005
Location: Chicago. (The less-murder part.)
Posts: 33,206
Total Cats: 6,708
![Default](https://www.miataturbo.net/images/icons/icon1.gif)
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.
#6
Retired Mech Design Engr
![](/mt2011/images_td/ranks/supporter1.gif)
Thread Starter
iTrader: (3)
Join Date: Jan 2013
Location: Seneca, SC
Posts: 5,010
Total Cats: 857
![Default](https://www.miataturbo.net/images/icons/icon1.gif)
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/attachments/race-prep-75/131836d1422136450-relays-switches-breakers-img_1355.jpg)
System, not installed
![](https://www.miataturbo.net/attachments/race-prep-75/131834d1422136450-relays-switches-breakers-img_1359.jpg)
Close-up of relay bank
![](https://www.miataturbo.net/attachments/race-prep-75/131835d1422136450-relays-switches-breakers-img_1358.jpg)
Remote switches mounted to top of roll cage for easy reach.
![](https://www.miataturbo.net/attachments/race-prep-75/131836d1422136450-relays-switches-breakers-img_1355.jpg)
System, not installed
![](https://www.miataturbo.net/attachments/race-prep-75/131834d1422136450-relays-switches-breakers-img_1359.jpg)
Close-up of relay bank
![](https://www.miataturbo.net/attachments/race-prep-75/131835d1422136450-relays-switches-breakers-img_1358.jpg)
Remote switches mounted to top of roll cage for easy reach.
Thread
Thread Starter
Forum
Replies
Last Post