Fusing battery + wires

[74carrera911]

All,
I've be researching additional fusing for my 74 Carrera build. fusing the instrument lights is on the agenda as well as adding relays for the headlights, (any other areas of a 74 vintage that need fuses?
Pertaining my subject title to add fuses/circuit breakers at the battery + , my search on this forum has come up empty, not sure if this due to it not being a practical idea or I'm using the wrong search words.
Has anyone added fusing/circuit breakers at the battery + to the fuse panel, ignition switch and possibly at the black cable to the starter? Fuse/breaker size?
Thanks

[T77911S]

fuses are there to protect wiring and are sized for the size of the wire they protect.
so if you put a 50amp fuse at the battery it wont do anything when the wires going to the fuel sender get hot and melt and start a fire. or a blower locks up and melts the wires.

the 50 amp will protect the wiring going to the rear of car to the starter and alt. .
50 is just for conversation, not a recommendation.

[Discseven]

74... I just dealt with electrical issues. Meltdown of wires and failing headlight beam selector switch in an '80. Working on that I installed a quick-disconnect at the battery. The knob-turn thing. That's a fine upgrade when dealing with car's electrical system.

Added dual relays for the headlights. There's a JWest product the host sells. Nice setup but questionable quality control for that part. I received it with the signal and power-out wires reversed. Waste of time sorting that BS out. Will elaborate on that if wanted.

I have a couple of electrical mods in car that are ganging up connections on the + battery post. That's getting messy. Just ordered a small distribution panel (below.) $17 not including shipping. This will clean up the + battery post and make future mods easy. Nice to have fusing built into this sort of hub.



Was a recommendation to fuse the instrument panel lighting circuit with either a 3 or 5 amp fuse.

Suspect in my electrical failure was the degrading connections at the fuse panel. I subsequently refreshed the entire panel's connections.

Was also recommended that the car's ground wire connections be refreshed. Daunting task to get them all. (John, you reading this?!) That will be done but over time.

There's surly more to do but that's my 2 cents to start the ball rolling.

.

[ChrisHoover]

There are many excellent threads on fuses. Use duck duck go search engine. Specify site:forums.pelicanparts.com Many results will pop up.

Best I can tell the original design had switches carrying current. You want to current limit the switches. Relays do that. Fuses don’t. Fuse will current limit the circuit and associated wiring. The key, headlight and high beam switch all carry current. Adding relays to these circuits moves the load away from the switches.

Fusing individual circuits is a good practice. It prevents catastrophic failure across multiple circuits and offers some protection from fire.

The youtube channel garage time has a good episode on upgrading the lighting circuits. He shows the hidden damage in the old wiring.

[kimlangley7]

Karl:

I'm is the process of adding an additional fuse block to my 80 SC. I've got some stuff I want to add - and don't want to tap into the OEM electrical system - planning on six additional devices added - some with relays [fog light ] some without .

There is a ton of information on the internet -

I plan on using a sheet of black hard plastic as the base - mold the plastic into a "L" shape config - attach the base vic of shock tower.. have a nice spot vic of smugglers box to route wires to instruments - voltmeter - hour meter. // Instrument console is the old gutted out console

kgl

[Tea Tray]

When adding a voltmeter consider routing the meter + terminal to the ignition, fuel pump, anywhere you may wonder if power is there when the engine doesn’t start. I’ve done this in a number of projects and it can be a day saver.

[Lyndon302]

I went to the wreckers.
Got a fuseable link off a jap car. Positive battery terminal then to the main cable.
Cost a dollar.
I have a battery isolater on the negitive leave in the horn grill.
I have a pull cable on the positive lead operated from inside .
Car is never left with the connected.
Lyndon

[74carrera911]

Karl, what you show in the photo is in line with what I would like to do. I’d like some additional protection for the battery wires going to the light switch. May not be absolutely needed but some peace of mind for those long wires. Wiring kits I’ve used for other hot rod projects had fusible links for the long run wires from the battery/alternator to the fuse panel. Seems like the right thing to do. Thanks all for the input.