Total newbie here!!! I was wondering if someone could help me with a question I have. I would like to be able to power my underbody neons by either using a switch that's in the car (it's a lighted switch), or by the aux. button on my remote starter. I believe I would need to use a relay...but I'm just not positive on how everything would hookup. I'm attaching a diagram below...if someone could tell me how I would go about hooking this up I would really appreciate it. I wasn't sure if I would also need to use diodes?

 

You can likely use a relay (with a reverse-EMF protection diode across the relay's coil), but first you need to give a bit more information so that a proper size relay can be selected and the diode polarity shown correctly:

1) Remote aux output - does this output alternate between "open" (infinite resistance) and "ground", or "open" and "+12v"?

2) What is the current (amps) or power (in Watts) rating of the remote aux output? (fuse rating would be perfect)

3) How much current or power (Watts) does your neon distribution block require? (the size of the fuse the neon installation manual told you to use is perfect)

 

You can likely use a relay (with a reverse-EMF protection diode across the relay's coil), but first you need to give a bit more information so that a proper size relay can be selected and the diode polarity shown correctly:

1) Remote aux output - does this output alternate between "open" (infinite resistance) and "ground", or "open" and "+12v"?

2) What is the current (amps) or power (in Watts) rating of the remote aux output? (fuse rating would be perfect)

3) How much current or power (Watts) does your neon distribution block require? (the size of the fuse the neon installation manual told you to use is perfect)

Thank you SgtWookie...hopefully these answer your questions:

1.) According to my manual it says I can set it to pulsed, timed or latched.

2.) It shows the Aux 1 output as (-) 500mA.

3.) In the installation manual, it shows 5A.

I really appreciate your help!!!!!

 

Ok, since it says the Aux1 output is -500mA, that means it can output 12V at up to 0.5A.

So, you get a relay that has a 12v coil which uses 500mA or less, that has SPST N.O. contacts rated 5A or better. One side of the relay coil goes to ground. The other side of the relay coil gets connected to your Aux1 output. At the same time, connect the anode of a diode (1N400x, x=1 to 7) to ground, and the cathode to the side of the relay coil you connected the aux1 output to.

Then for the contacts - one gets connected to somewhere between the powered (always on) side of the switch and the fuse for the switch, the other side to the distribution block +12v input.

 

Thanks for the reply! I've edited my diagram...but I'm thinking I still might not have it right...would you mind taking a look at it and let me know what I've got wrong? What I'm hoping to do here is to be able to turn the lights on or off by either using the switch inside the car, or by using the remote. So I was thinking that I would need to have both the Acc wire from the switch and the aux wire from the remote both going to the same contact on the relay...but I'm just not sure. Sorry for all the questions on this!!

 

I've made some corrections to your schematic.

Since the switch you are using is capable of supplying at least 5A of current, there is really no point in using it to energize the relay. More importantly, it isolates the aux1 output of your remote from the output of the switch, in case the documentation isn't correct. Connected the way I've shown, the worst that will happen is that the relay coil won't energize.

 

I've made some corrections to your schematic.

Since the switch you are using is capable of supplying at least 5A of current, there is really no point in using it to energize the relay. More importantly, it isolates the aux1 output of your remote from the output of the switch, in case the documentation isn't correct. Connected the way I've shown, the worst that will happen is that the relay coil won't energize.

THANK YOU VERY MUCH!!! I'll try this out after I order the parts...I really appreciate this!!!!

 

You're welcome

Note the direction the 1N400x diode is connected; the anode is to the ground side of the relay. This protects your aux1 remote output from the large reverse voltage spike that will occur when the aux1 output stops supplying current to the relay's coil, which is an inductive load.

It would be a good idea to add a ceramic capacitor (around 470pF-2200pF, or 0.47nF-2.2nF) across the diode. Rectifier diodes like 1N400x, 1N540x are fairly slow to turn on and off. The capacitor absorbs the sharp peak, and gives the diode more time to turn on. Your remote will have a longer and happier life.

 

OK, I have this setup like the picture shown below and I'm able to turn the lights on and off by either the switch or the remote. What I was wondering is could this setup be modified so that if I turned on the lights by the switch, I could then turn them off by the remote (and visa versa)?

 

Thanks for the reply Alberto...however I'm not sure I follow your diagram. Would it be possible that you could show what you are saying by modifying the diagram I have in my prior post? Again what I'm trying to find out is can the setup I currently have be changed to allow the following:

- If I turned the neon lights on via the switch, then be able to turn them off via the remote (and visa versa).

Thanks!!

 

You'll also need to buy new batteries more often, because if the relay's coil is left energized by the remote, it will drain your battery.

 

You'll also need to buy new batteries more often, because if the relay's coil is left energized by the remote, it will drain your battery.

Thanks for the reply SgtWookie. The reason why I want to do this is so that if let's say I turned the lights on with the switch in the car, then later I realized that I forgot to turn them off, I was hoping my setup could be modified to allow me to turn the lights off from my remote. Are you saying that if I were to set it up this way, it would drain my car's battery?

 

The way Alberto suggested to wire it could lead to the relay coil being energized with the lights and car off.
Automotive relays have the following connections:
30: COM - the common terminal for the contacts.
85, 86: Solenoid winding.
87: N.O. contact.
87a: N.C. contact. (Not all relays have the 87A terminal. If they do, it is in the center, and parallel with the 87 contact blade)

Alberto's schematic is typical for how 3-way wall switches work in homes. However, those are manually operated.

If you look at that schematic for a bit, and consider that in your application one of the switches will be a relay, you will realize that in one position the coil will be energized, and it is possible for the neon lamps to be turned off, yet the coil of the relay is still energized.

If you leave things the way they are but connect the manual switch power supply to the ACCY circuit, it will not supply power to the lights when the ignition switch is in other than the RUN or ACCY position. They will turn off when the switch is turned to START or OFF, unless the remote has turned them on.