Question - LED conversion, Resistor

Hey guys,
I did an LED conversion on my turn signals in one of my Jeeps.

I solderd the resistors in and left them hanging in small gap behind my signal covers.

Well, I wanted to see how hot they got after driving around for most of the day.
I popped the covers off and found both resisters stuck to the plastic housing.
There's no place to mount these things away from everything else.

So...
I was wondering, can I loosely wrap my resistors in tin foil?
Sort of acting like a heat sheild to protect the other wires in the housing?
Or will that bake my resistors?
They reach a temp of 65 c according to the box they came in.

a reply to: Macenroe82

Not sure how much space you have to play with, but you would probably do better by giving them an air gap around them. Perhaps some sort of spacer like some stiff wire twisted around the resistor body, with the ends sticking out to hold it away from the plastic.

You could also extend the wires out into an area with more 'room' for the resistors and mount them there. You could you fix them hard against the car's metal with something. That would also be a bit of a heat-sink.

a reply to: chr0naut

And that was the original intention!

With my Jeep cj7, it was almost too easy to install the LED kit.
There's just so much damn room in every spot of the vehicle.

But with my new Jeep, as is with everything now, everything is so packed together, there's just no space.

I do like your idea about wrapping the resistor with a wire - similar to my foil idea.

Another option I could do is extend the wiring through the rubber grommet, and feed it down into the wheel well, and perhaps mount to the chassis.
But that's a Lot of work for such a small job.

Do you think that the foil will bake the resistor?
To be clear it just for the turn signals I'm having this problem.
Everything else is good to go and are mounted far away from plastic or wires.

originally posted by: Macenroe82
a reply to: chr0naut

And that was the original intention!

With my Jeep cj7, it was almost too easy to install the LED kit.
There's just so much damn room in every spot of the vehicle.

But with my new Jeep, as is with everything now, everything is so packed together, there's just no space.

I do like your idea about wrapping the resistor with a wire - similar to my foil idea.

Another option I could do is extend the wiring through the rubber grommet, and feed it down into the wheel well, and perhaps mount to the chassis.
But that's a Lot of work for such a small job.

Do you think that the foil will bake the resistor?
To be clear it just for the turn signals I'm having this problem.
Everything else is good to go and are mounted far away from plastic or wires.

I think that foil is probably too thin to have much of a heatsink effect.

Perhaps if you bulked the foil up and spread some heatsink compound like the use in computers (Arctic Silver is one brand), into the foil, and then used the foil to hold it in place. But ultimately, the heat is dissipated to the air, so an air gap would be better (IMHO).

a reply to: chr0naut

Good plan.
I also have some exhaust tape.

a reply to: Macenroe82

Why not just use a higher rated resistor, they shouldn't be getting that hot.

There are resistance calculators on the web that might help you.

LEDs use a resistor as a current limiter. You can control how much current they draw depending on the value of the resistor. If they draw enough current to heat the resistor up that much, the resistor needs to be of a sufficient power rating to safely dissipate the heat. Reading that you wanted to try wrapping a resistor in foil caught my attention because that's something you just do not do. You can use a ceramic/cement high wattage resistor or a metal-finned resistor but please for safety sake, never ever wrap one in foil. That's a good way to start a fire.

a reply to: HalWesten

Thank you!
That's what I was looking to hear, if it can or not be done.... Without damage to the thing.

The Resistors are:
SYLVANIA
12 V, 6 Ohm, aluminum heat sink - corrects hyper flashing.

But, as with most new vehicles, everything is plastic.
It's sounding like I might have to fish the wire through the grommet, and Mount to something metal behind the wheel well....
Which is what I was hoping to avoid.

a reply to: AugustusMasonicus

That's the thing, these were the ones recommend by the automotive supply store.
I think it's just a matter of having them properly mounted on a metal surface.

Normal flashers work with a heat trigger, meaning the current flowing through it is high enough to trip it like a circuit breaker that automatically resets. That's why they wear out over time. LEDs don't draw the current that an incandescent bulb does so they don't generate the appropriate heat through the flasher. That's why so many people have poor results converting their systems to LEDs. So when you convert you generally have to use the aforementioned resistor. Resistors generate heat by limiting current and that energy has to go somewhere.

The heat sinks on some of them are massive, but also usually designed conservatively to prevent resistor failure. If yours melted the plastic I would ask the store again about the resistor value, it may not be correct.