EdSR. You do not wan't to use fusable links. Go to a Naapa auto parts. They carry small fuse blocks and good inline fuse holders. A fusable link is an accident waiting to happen on a racecar unless it's used as a main power supply wire right at the battery. Even then I would not recomend using one. You can put a large inline fuse at the battery or source of accessory power. Also available at a Nappa parts store. They make large 2 prong fuse holders and you can get from 40 to 80 amp fuses for these. I believe they are on a 8ga wire. As for the electric fan , if it were me Iwould run it off a 12 volt relay to carry the load. The electric fuel pump will be fine with a fused 12 ga wire. I see you are in the Flint area, you could try calling State Wire and Terminal in Davisburg,Ithink that is close to you. They are our electrical supplier and carry all these if your local Napa dealer don't have them.The relay is not hard, a large main power wire, a 12 volt trigger wire to turn it on fromyour switch,ground wire, and power out that goes to your fan. I really like the Napa rely, i use them on heavy equipment all the time and they will carry 40 amps load. They only cost about 10 or 12 bucks. If you need help wiring the relay PM my son and I would be glad to give you a call.Hope this helps,good luck.Ed SR.

 

Heres the schematic I planned to base my wiring on. I intended to use 40 amp relays on all my electrical parts. So you recommend I use inline fuse holders in the place of where it shows fusible links? If so what amp ratings do I use?

I actually drive a truck locally for Holland and was at State wire about a week or so ago delivering large reels of wire so I know exactly where you are talking about.

I may need to talk to one of you to help get this straight in my head.
Thanks for the help

Brian

 

EdSR. glad to see you are using a diagram.In that case go ahead and use the enclosed type fusable links w terminals. Do not use the old straight wire type, because they fizzle like a sparkler if they do burn out. I would use links rated at 50 amps or more for the relays and the heaviest i could get for the main power and alternator wires , the two 8ga wires. I would fuse the switches that turn on the relays w 10 amp fuses to be safe. Its a simple diagram just take your time when you do it . Good luck w your race car EdSR.

 

Yeah, i'm not in any hurry to burn my car to the ground. Thanks for the help I really appreciate it.

Brian

 

EdSR. I checked my parts bin today. napa 40 amp relay,part #192d. Napa plug for relay,part#9185. The fusable link we use are 40 amp. rated for these relays. I don't know why I told you 50amp yesterday, my mistake. You still need to run bigger fusable links for the 8 ga alt. and power, they make 60 and 80amp. I found them in State Wire and Terminal book today. Heres the easy part if you buy the Napa stuff.Plug in your Napa relay to your Napa plug and as follows.Red wire battery pos.,Black wire ground,Green wire to switch, Yellow power out,White also power out. We use these all the time for heavy load circuits and they hold up well. Got to get back to work, Ed SR

 

I have a wiring kit I bought for my Fuel pump that came with a relay and a circuit breaker. Is there a difference or a benefit between using a fusible link over a circuit breaker or vice versa?

Thanks for the extra info. I'm not sure theres a Napa in the Flint area though. I can definitely go to State Wire though.

Thanks again,
Brian

 

The fusible link acts like a fuse as it will burn out in the event of a short.That is what you want. A circuit breaker will reset itself after it cools off,feeding power back to the source of the problem and can burn up wires. not what you want. Ed SR

 

Thanks again

 

Ok more questions. On the Napa relay would I use both the yellow and *********** out terminals or do I only need to use one?

 

Just 1 wire, both same output. If you look on the bottom of the relay in your fuel pump kit at the base of the terminals they are numbered. Most of these relays are pretty much universal mostly made by Boshc and a couple other manufac's. Anyhow #87 should be power out. 1 of them mighthave a symbol next to it but it don't matter which one you use.I don't rember all the numbers, but i'll look tomorrow and get them to you. That way if you are using a plug w different wire colors you will know what you got.Take care EdSR

 

Hi Brian, the numbers are as follows. #30 batttery #85 ground #86 switch #87a #87 power out.There is a 4 prong version also you might run into when buying more relays. It is exactly the same except only one #87 term. you can use a 5 prong plug on it also.just clip off the extra wire. You can use a 4prong plug on a 5terminal relay, might have to clip off the extra #87term. Have done it both ways many times. This should get you going. One other thing, State Wire might just have a generic plug w all same color wires so watch the numbers and where they go to, if thats what you get. Have fun,Ed SR

 

Thanks. I'm gonna dig into it this weekend.

 

Most automotive relays use this typical pin-out:
Pin 86 = Coil +, Energizes Relay - Triggers relay on (Typical)
Pin 85 = Coil - , Grounds Relay (Typical)
Pin 30 = Common, Usually Battery Power (+) (Typical)
Pin 87 = Normally Open, Switches to a closed state when relay is energized (Typical)

Pin 87A = Normally Closed, Switches to a Normally Open state when relay is energized. (Non Typical)

Any 5 pin relay can be used for 4 pin applications.
Most all relays use this “typical” number configuration.

A “typical” 5 pin application is used for Nitrous override while on the Trans Brake applications.

A relay should be used for Water Pump, Cooling Fan, Fuel Pump and/or other high amperage output components.

A relay was designed to take the load off of a switching device (Toggle Switch). When installed properly, it’s the best way to provide adequate power supply and the most efficient way to supply power to a component.

In comparing a toggle switch to a relay, I don’t feel that there is a toggle switch available that will supply adequate power to a component efficiently.

Without the use of a relay and an effectively wired car, you leave risk of:
A.) Overheat the toggle switch.
B.) Prematurely wearing out a component.
C.) Tearing up other components of an electrcial sytem due to inadequacies.

If a component is properly set up with a relay, adequate wire size and proper ground, you will get the best long lasting performance and reliability out of a component.

I hope this helps,
Sparky

 

Thanks for the added info. Every bit helps.