Regulating voltage to a relay question

Quick question.

I have interior LEDS hooked up to my truck thru an add a fuse. They work great. I have these LEDS relayed (SPST) to mimick the dome lights on/off/door. When I open the door and they are set on "door" as the voltages goes up and it begins to open the relay there is a terrible sound from
The relay like gears grinding almost. This doesn't happen when it's an on/off immediately type of thing. Which is great. So here's my question.

What can I or should I attach to my wire running to my relay so it will not allow current to go thru until it reaches a certain level. I'm assuming I'll need to attach it to the wire running from the 85 pin?

Or is there a way to just stop the dimming function of the "door" lights all together?

 

The BCM controls the ground side of the dome light circuit. for the dimming effect, this is done by using PWM (Pulse With Modulation) of the voltage. The relay makes one heck of a racket during this process of shut down and start up. unfortunately you have to either wire the ground on the LEDs directly to the BCM wire (if a small amp load) or look into a solid state relay. SSR are not cheap by any means. expect 30 to 40$ for one of those.

 

YES!!!! That is exactly what I was looking for!!!!! The racket on the current relay is Terrible!!! It sounds like there is something trying to grind its way thru the side panel!!! You'll have to forgive me this is the first time I've done any wiring with a Relay, so this SSR will not have a racket I'm assuming it works by circuitry and not mechanical like the other relay I used (like a solid state hard drive).....are there any important safety tips I need to know about this??? Does it get really hot it looks like all those little pins on top are heat sinks....anything else I need to know any particular brand I should or shouldn't go with??? No sound at all on this right???

 

Some further questions for you @fergyz or anyone else who might know the answer.

If I do go with the SS Relay is the wiring different somehow?? I've been seeing stuff about how it's not the same as a regular mechanical switch. The other question is do I have to also put in a diode, I saw some stuff about voltage leaks with these SS relays.

Exactly how would I attach the wire to the BCM wire.....is there a particular one that I would ground it to so that it would still do both door and on function with the dome lights.

 

No mechanical parts = no noise. this is just like a SSD hard drive. this type of relay will get hot if wired incorrectly, if you exceed the amp rating for the relay or run the relay at max amps for an extended periods. as for you using it for such a low amp circuit for very short periods of time, i don't see the need to worry about heat issues. the hella is the first one i have seen that looks and is sized for a normal automotive relay socket. there are other's out there but they are more geared towards big appliances. some also are for AC instead of DC voltage. i think as for ease of installation, the hella one is probably your best bet.

 

the wiring is no different than a standard automotive relay.

pin 30 = battery voltage
pin 87 = positive lead of LEDs
pin 86 = constant 12v (can be jumper-ed from pin 30)
pin 85 = connected to the BCM wire (blue)

i haven't had any issue with voltage leaks with an install i did... but i am not going to say that it's not possible. from what i quickly read about them, i think it's more geared towards AC circuits and/or the way they are wired with certain components on the input side.

i don't think you are going to have the issue. The BCM is the one that provides the ground and that doesn't happen until it switches the circuit on.

 

Found you!

 

how did you exactly wire up your lights in the first place? i'm just curious on how you went about it with your first relay job.

 

Thank you for answering all my questions. I really appreciate your help/guidance.

Here's how I did it.

5amp fuse from add a fuse to the 30
Brass side of dome light to the 86(pink wire)
Silver side of some light to the 85 (tapped the extra lead I had made from running the wire from my map/dome light on with the doors mod
Led string (in parallell) from the 87
Grounded the LEDs in the engine compartment.

Everything works well just hate the noise of the stupid mechanical relay! I went ahead and ordered the hella relay like you had pictures from del city. If I sell this truck that thing is going with me.

 

Stalker lol

 

I go where the knowledge is...

 

Ha me too!!!! I couldn't have done any of this without these guys helping

 

That's actually is very good for your first go.... a relay can be wired a few different ways to get the same result.

 

Thank you sir! I already learned something from you about jumping the 86/30 pins. I didn't realize that could be done just never thought about that Would have saved me some frustration with that damn pink wire. That's good stuff to know!!

Anymore fun things I can do with these things?

 

the way you went about wiring the circuit actually worked the best with the stock dome switch. running wires to up to the dome light can be a pita for some.

jumping the pin for power is not always ideal but in the case of needing a constant 12v to pin 86, that's the easiest way to go for a negatively controlled circuit (applying the ground completes the circuit).

This way is more geared for tapping into the dome wire at the BCM. this would only activate the lights with doors open/keyless entry-exit. the dome switch would have no affect on this

 

Yes tapping that dome light was a pain in the ass I won't try to downplay that.

This was the end result I'll be posting a more in depth wrote up in the lighting forum likely later today

Rear seat








I realize the front look blue but they all came from the same LED strip and are pretty white the rear seat photo shows the color the best.

I like I can do on/off/door with the dome switch. Really didn't want to only have them on with the door. Gotta have the control.

 

there a lot of ways and uses for relays.... http://www.the12volt.com/relays/relays.asp

 

a simple SPDT switch could easily give you that control. it's the same type switch in the dome light

 

Ha I've gotta go learn about them next