2 wiring questions.

[oino]

Items that need or should have a relay. I know horn and fan. Anything else?

Other question on a chevy 3 wire alt.. The sensor wire or #1 wire out of the plug.
How is this wired? Right now I have it going to a toggle switch by its self.
Do I need the switch or can I just run it to a dummy light and be done with it?

P.S. I'm not running a key switch in my car.

 

[409T]

Use a relay for the electric fuel pump if you have one, some people like to use them for the headlights as well.

 

[Keeper]

I only used a relay for my headlights. Did not use one for the horn. I used a Rebel Wire harness.

3 wire is pretty easy, white is for the light, red goes to the terminal on the alt, which then goes to the battery.

 

[Keeper]

I was wrong, seems the Rebel harness does have a relay for the horn.

 

[RPM]

I only used a relay for my headlights. Did not use one for the horn. I used a Rebel Wire harness.

3 wire is pretty easy, white is for the light, red goes to the terminal on the alt, which then goes to the battery.

If you run the white wire to the ignition switch, be sure you put it on the acc post. If you put it on the ign side, you won't be able to shut the engine off.

 

[oino]

So I can just run the white wire on the alt to a light and not a switch.

Why a relay for the headlights?

 

[409T]

Why a relay for the headlights?

It lets you run a switch that might not handle the current draw of the headlights.

 

[PotvinGuy]

It lets you run a switch that might not handle the current draw of the headlights.

Conventional headlights can draw 10 amps or more each. Double that and add some taillights and you've got a lot of juice. I like relays because they keep heavy current out of the dash, so you can use smaller wires (I use 20 gauge) and any switches you want. I run all my dash wiring thru a multipin connector, so it's easy to pull it and work on it.

I also use a relay in the starter circuit; the starter button on the dash controls the relay, which in turn controls the starter solenoid. Also relays for my electric water pump and my electric fuel pump.

 

[oino]

Conventional headlights can draw 10 amps or more each. Double that and add some taillights and you've got a lot of juice. I like relays because they keep heavy current out of the dash, so you can use smaller wires (I use 20 gauge) and any switches you want. I run all my dash wiring thru a multipin connector, so it's easy to pull it and work on it.

I also use a relay in the starter circuit; the starter button on the dash controls the relay, which in turn controls the starter solenoid. Also relays for my electric water pump and my electric fuel pump.

How do you wire a relay for the starter?

How can I use a relay for my acc toggle switch?
The switch I have their now. Has an led in it. But it burnt out a few min. after having it on.
The switch still works.


Death ray LOL I need one.

 

[PotvinGuy]

Like this:

For your accessory switch, substitute it for the starter button in the diagram, and put the load (light, pump, etc) where the starter solenoid is shown.

Not sure why the light burned out. If it was an LED, it may have needed an external resistor to limit the current. LEDs are essentially diodes with no resistance and hooking them to any voltage without a resistor in series will burn them out. If you have any documentation on the switch, lemme know and I can help.

 

[oino]

Like this:


For your accessory switch, substitute it for the starter button in the diagram, and put the load (light, pump, etc) where the starter solenoid is shown.

Not sure why the light burned out. If it was an LED, it may have needed an external resistor to limit the current. LEDs are essentially diodes with no resistance and hooking them to any voltage without a resistor in series will burn them out. If you have any documentation on the switch, lemme know and I can help.

thank you.

Nothing came with the switch. I got it at napa. part # NW 786127
Had a red led in the front.

On the diagram where you have the + going in. Is that straight from the battery or switched acc. from the fuse panel?

 

[PotvinGuy]

Depends. I'm gonna guess you are using a wiring kit and an ignition keyswitch, not a separate starter button like I do, in which case the control to the relay would come from the ignition switch "start" connection, or the starter wire from the fuse panel (I've never used a wiring kit). The power to terminal 30 of the relay could come straight from the battery or from fuse panel switched or any hot wire.

Re your switch, it's a Dorman 84894, with 3 terminals. The center terminal, #2, goes to ground. Terminals 1 and 3 go to power and the load. Which is which determines whether the light stays on all the time, or just when the switch is on. The packaging would have had the instructions. The light is an LED, and it is for 12 volts; if more voltage was connected, the LED could burn out. What are you controlling with the switch? Some loads can generate a spike, usually when switched off, that could burn out the LED.

 

[oino]

Depends. I'm gonna guess you are using a wiring kit and an ignition keyswitch, not a separate starter button like I do, in which case the control to the relay would come from the ignition switch "start" connection, or the starter wire from the fuse panel (I've never used a wiring kit). The power to terminal 30 of the relay could come straight from the battery or from fuse panel switched or any hot wire.

Re your switch, it's a Dorman 84894, with 3 terminals. The center terminal, #2, goes to ground. Terminals 1 and 3 go to power and the load. Which is which determines whether the light stays on all the time, or just when the switch is on. The packaging would have had the instructions. The light is an LED, and it is for 12 volts; if more voltage was connected, the LED could burn out. What are you controlling with the switch? Some loads can generate a spike, usually when switched off, that could burn out the LED.

I'm running a push button to start the car.
Ran all my own wire. The switch is the acc. or on switch to the fuse block.

 

[PotvinGuy]

OK, the diagram I sent is fine for your push button. That switch is only rated for 30 amps. If you're supplying the whole fuse panel, and therefore all the power to the car, you could be pushing your luck. I'd insert a nice 70 amp relay in the circuit to make sure you don't fry the switch. Here's one: http://www.summitracing.com/parts/aww-500511/overview/

 

[Joe-405]

I've gotta ask potvinguy what's the death ray relay for ????

P.S. didn't mean to thread jack but its got me stumped.

 

[PotvinGuy]

I've gotta ask potvinguy what's the death ray relay for ????

P.S. didn't mean to thread jack but its got me stumped.

It's really the water pump relay. I just like to mess with people...

 

[oino]

Speedway has that 70amp relay. I'll go get one tomorrow

I'm guessing that would go before the toggle switch.
30 would be + from the Battery,
85 Ground, 86 and 87?

I'm using a pull/push headlight switch.
Can I use a 40amp relay before that or use a 70amp there too?

 

[PotvinGuy]

Speedway has that 70amp relay. I'll go get one tomorrow

I'm guessing that would go before the toggle switch.
30 would be + from the Battery,
85 Ground, 86 and 87?

I'm using a pull/push headlight switch.
Can I use a 40amp relay before that or use a 70amp there too?

Just like the diagram, but put the switch where the button is, and 87 goes to the fuse panel.

The headlight switch is probably OK by itself (it's designed for the load), but a 30 or 40 amp relay could be used there too, and that is just a $5 relay.

 

[oino]

Just so I understand.
Like this right?

 

[PotvinGuy]

That's it. And I would replace that switch. The fact that the LED burned out makes me suspect the switch got hot and could be messed up.