Relay Wiring

[CarbonSteel]

I am confused by one thing on this wiring and want to be sure that I have it correct. One of the Jeep forums that I am on posted a nice write-up of how to wire the side-step lighting, I translated the wiring connection text into a picture using the schematics of the AOLE ASH-DD25 relay.

When the relay is energized, how do terminals #1 and #2 connect to one another to pass 12v to the lights? It is confusing, since it seems that terminal #1 and terminal #4 would be pass through once the relay is energized as would terminal #3 and terminal #2.

What am I missing here or will this work?

For the Relay
#1 + Red wire going to your lights
#2 + Red wire going to your battery/fuse
#3 + Blue trigger wire that will get power with the interior/door lights
#4 - Two black ground wires, one from the lights and the other going to the battery

 

[CT8]

I would guess Wires 3 and 4 is the voltage to turn on the wire 1 and 2 circuit. Solid state relay?

 

[CarbonSteel]

Originally Posted by CT8
I would guess Wires 3 and 4 is the voltage to turn on the wire 1 and 2 circuit. Solid state relay?
Yes; it is a solid state relay. The confusing part for me is there is a positive and negative terminal on each side of the relay. The left side (control side) makes perfect sense, it is the right (load side) that has me scratching my head. Since terminal #1 is denoted as negative, it did not make sense to me that it would make a connection with terminal #2 which is denoted as positive because that would seem to create a short circuit would it not?

 

[CT8]

Would checking out the voltages at all points to see what is going on help to figure out the wiring. Electronic controls can be strang until it is understood how they work, not fun.

 

[55hambone]

What the drawing has labelled as "load" would be your lights. The arrow that you show for 12 volt positive to lights should be drawn pointing to the side of the load (lights) that is labelled 1. The statement "#1 + Red wire going to your lights" is correct, but your arrow points to the negative side of the load, not to #1. It is not a short circuit because the load is between the positive and negative terminals.

 

[Sunnyinhollister]

The LED biases the transistor allowing it to "turn on" or allowing the current to flow. If the polarity was reversed, there would be no current flow.

 

[CarbonSteel]

I figured it out with the aid of a 12v DC power supply and my trusty volt/ohm meter. Terminals #3 and #4 (control side) do not pass any voltage to terminals #1 and #2 (load side). When the control side is energized, there is a circuit created between terminals #1 and #2. Question answered and now to wire it all up.

 

[CarbonSteel]

Originally Posted by 55hambone
The statement "#1 + Red wire going to your lights" is correct, but your arrow points to the negative side of the load, not to #1.
The #1 terminal is marked as negative both on the schematic I posted and the actual relay as shown below and I am pointing to terminal 1 in my annotated schematic for positive to the lights. Look again at the schematic and you will see the "1" to the left of the minus sign for terminal 1.

 

[Dinoburner]

Without more info this relay makes no sense. It`s been 10 years since I`ve read a schematic and this one needs a legend. Never mind see it now

 

[CarbonSteel]

Originally Posted by Dinoburner
Without more info this relay makes no sense. It`s been 10 years since I`ve read a schematic and this one needs a legend.
See my post above, I figured it out. Basically when power is applied to terminals #3 and #4, terminals #1 and #2 are a switch that is closed making a circuit so the power from the battery attached to terminal #2 can flow to the lights attached to terminal #1.

 

[Rand]

That isnt intuitive but I'm not an electrical engineer.

So you get trigger power to terminal 3 it is then grounded on 4

on the other side the incoming battery is 2 when 3 is powered it connects 2 to 1 which is connected to the lights positive (despite having a negative sign next to it)

I could wire it up easy enough knowing that.. did it come with an instruction page or anything?

 

[clinebarger]

#1 is the load which has a path to ground through the component being powered. Amperage flow matters with a Transistor.

There aren't many automotive uses where a Solid State relay is needed outside of strobing, A Electromagnetic relay would have been more than suitable for this application. And Polarity doesn't matter.

 

[CarbonSteel]

Originally Posted by clinebarger
There aren't many automotive uses where a Solid State relay is needed outside of strobing, A Electromagnetic relay would have been more than suitable for this application.
In this case, I am using it to power the LEDs in the side steps and the internal light power (trigger) fades and an electromagnetic relay would chatter and not function properly. Others on the Jeep forum tried them and switched to solid state.

 

[WyrTwister]

Originally Posted by clinebarger
#1 is the load which has a path to ground through the component being powered. Amperage flow matters with a Transistor.

There aren't many automotive uses where a Solid State relay is needed outside of strobing, A Electromagnetic relay would have been more than suitable for this application. And Polarity doesn't matter.


Kind of what I was thinking . A relay is a switch , except it is activated by an incoming electrical / voltage source . In stead of being activated by your finger .

I have almost no experience with solid state relays , but I would use one as I would an elector-mechanical relay .

You are correct , the solid state relay does not really have a great advantage over an elector-mechanical relay . But , as long as the OP gets it working OK , it does not hurt anything . Which cost more , I do not know ?

 

[WyrTwister]

[/quote]In this case, I am using it to power the LEDs in the side steps and the internal light power (trigger) fades and an electromagnetic relay would chatter and not function properly. Others on the Jeep forum tried them and switched to solid state.
[/quote]

Had not considered that possibility . How long does/do the side step LED's need to be on ? Lust long enough to enter the vehicle ? How much power do the LED's consume ?

 

[CarbonSteel]

Originally Posted by WyrTwister
Had not considered that possibility . How long does/do the side step LED's need to be on ? Lust long enough to enter the vehicle ? How much power do the LED's consume ?
They remain on for as long as the inside lights are on. So when approaching the vehicle, I typically unlock the doors, which illuminates the steps. They then fade as the interior lights fade.

There are 8 lights (4 on each side) and are 11 watts each. The relay is overkill for size, but I did not want the internal lighting circuit carrying the additional load.

 

[supton]

Some of the solid state relays do not support ac current. The load side is dc only, and current is only allowed to flow one way--if you hook it up backwards they are likely to flow current through a diode and the load will be stuck on. They do that because if they used two MOSFET's in series as a transmission gate then they increase the on resistance, and in many DC circuits that just isn't needed.

A solid state relay shouldn't wear out--no moving parts to get corroded with time, carboned over from arcing, and no wear points. They might switch on faster (might not be of interest for lighting). But anything can break... They can often have lower power required to actuate, the standard 12V auto relay is something like 100mA for the coil (quick look at a Panasonic CB1). Also they are current driven devices and as such can be switched on / controlled by something other than 12V, and that controlling device doesn't have to worry about inductive loads.

 

[CarbonSteel]

Completed my side step lighting installation this afternoon. It took 1 full day (2 half days). I spent a lot of time installing the wiring in split loom tubing, heat shrink wrapping all of the connections and routing the wiring through the frame. I tapped into the footwell light power and removed the passenger seat to make it easy to push the wire through the firewall boot and make the underdash terminations. I used marine grade 16/2 wiring to make the harness and double heat shrinked all of the connections under the vehicle. I added a 10AMP waterproof fuse into the battery feed and a 5AMP waterproof fuse into the trigger wiring along with a roadmaster diode.

Very pleased with how it turned out. A photo of the underhood relay and aluminum relay heat sink (I ordered another Jeep branded bolt to take the place of the silver bolt shown here):

 

[gamefoo21]

That is a simple relay, they are using electron theory to label the mount points.

Negative is power in aka Input.
Positive is power out aka Output.

Simple simple.

Refresher course

Electrons have a negative charge. They flow towards the the load or positive terminal.

 

[CarbonSteel]

Originally Posted by gamefoo21
That is a simple relay, they are using electron theory to label the mount points.

Negative is power in aka Input.
Positive is power out aka Output.

Simple simple.

Refresher course

Electrons have a negative charge. They flow towards the the load or positive terminal.

It is basically a switch. I figured out the wiring some time ago with a tester and completed the wiring on my Rubicon a week or so ago.