LED Courtesy light not working

[da_raabi]

I was looking to replace the courtesy light (the little one in the plastic housing under/behind the bottom-center of the dash) with one of these LEDs:

https://www.amazon.com/dp/B018KIU5SK?ref_=pe_1196280_123950170

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I verified the bulbs work (using the brake light socket), but they do not seem to want to work at all in the courtesy light. The socket works, because the standard incandescent bulb works fine. So am I doing something wrong? Did I just get the wrong bulb or something?

 

[da_raabi]

Nobody? Am I missing something simple?

 

[75Monza]

Is the wiring stock? If it was ever changed, an incandescent will still work, but LED won't because they are polarity sensitive. You can use a meter or just a test probe to see if the center pin or the case of socket is hot. Ran into that with the cigarette lighter in my car, somebody swapped the wires when they broke the plug and rewired it.

 

[75Monza]

Another thing is if these LED's are the cheaper kind that don't have the built in resistor, you may need to put a resistor across the leads to make it work because the amp draw is so low the circuit appears as open. Here is a good description I ran across for how to calculate what resistor to use.

A typical 1157 bulb (dual contact turn signal bulb) pulls ~ 2 amps during the bright part of the blink/braking, and ~ .5 amps running as a tail light.
1156 (single contact tail light) draws ~ 2 amps.
Marker lights like 194's draw ~ .3 amps.
LED bulbs usually draw about 1/10 the current that their incandescent equivelant does.
To simulate the filament load on an LED bulb, you need to use ohms law to determine the resistance and required power rating of the resistor for each bulb circuit (where 1157's have two circuits):

E/I = R and (I)(E) = P

1157 turnsignal circuit shunt resistor calculation:
(I'm rounding down since the LED will draw some of the current)
resistance = 13.8 / 2 = about 6 ohms
power rating = 2 X 13.8 = about 25 Watts
Using this calculation, to simulate an incandescent bulb on an LED 1157 turnsignal circuit, you need a 6Ω 25W resistor.

As a general rule, just figure avout 25W per bulb in your selection of resistors.
The resistors are wired in parallel with the load, so these resistors are wired across the bulb in parallel with the filament.

 

[yevgenievich]

Also verify that the center pin does in fact reach the bulb when inserting. There are different sockets with the mounting slots at different heights. But polarity is a more likely culprit as mentioned above. LED bulb should light up given 12V on one side and ground on other without needing a parallel resistor on a simple on/off circuit.(assuming built in current limiting resistor)

 

[75Monza]

Also, looking at the comments of people who bought this item, there might not be enough solder on the center contact to make a perfect fit in different sockets.

 

[theblindchicken]

Ran into the issue once that there wasn't enough solder on the LED bulbs to ensure a proper contact in the socket. Also had an issue with some that had a bad tab on them that didn't stick out very much so it wouldn't catch and prevented contact thus leaving the socket open.

 

[da_raabi]

Well I tried adding solder to the bottom pins on the led. That did not help. I'm going to check polarity on the wires next and compare against the brake light socket (where the LED worked fine). I don't think anybody has done anything with the wires for this light, but we shall see.

This is the first time I've had an issue with an LED conversion. Pretty funky.

 

[da_raabi]

Still fighting this one. I tried building up the contacts with solder, no bueno. Verified polarity of the wires against the brake light socket (which this bulb works in) and they were the same. No bueno. I fiddled around inside the socket (with the bulb installed) with my multimeter probes, and got the bulb to flash on once. For a split second. Then the fuse popped. WTF am I doing wrong? I am so thoroughly confused it hurts my head!

Why is a friggen light bulb beating me like this???

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[yevgenievich]

Sounds like there is some sort of mismatch of the bulb in the socket. Either the center or the sides are not making a good contact

 

[Cuba]

Then more than likely issue lies with a resistance issue. See 75Monza's post above. Spot on with the info provided. LEDs are not "plug-n-play" like a regular incandescent. They need a resistor to work with 12v systems. The bulbs you purchased may not have them built in.

Be sure the built up solder isn't touching each other. The fact you blew a fuse with LED makes me think this is a possibility

 

[theblindchicken]

Just out of curiosity, you dont happen to be using a dual contact bulb in a single contact socket or vise a versa?

 

[da_raabi]

Just out of curiosity, you dont happen to be using a dual contact bulb in a single contact socket or vise a versa?

Sure am. Looks just like this:

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The incandescent I replaced was the same way, and it worked just fine. Could this be my problem though? I did notice that the brake light socket (where this works) had two little "bands" for contacts in the base of the socket. The courtesy light socket has only one, and it is left-to-right while the brake sockets was top-to-bottom.

Could that be it? I just have the wrong type of bulb?

 

[Cuba]

I did notice that the brake light socket (where this works) had two little "bands" for contacts in the base of the socket. The courtesy light socket has only one, and it is left-to-right while the brake sockets was top-to-bottom.



Could that be it? I just have the wrong type of bulb?

I believe you're correct there. The 2 solder points on the end are for each filament in a regular incandescent bulb. 1 for parking lights (dim filament), the other for brake (bright filament)

The courtesy light should only have 1 solder joint on the tip. The bands you speak of are the little ******* that lock the bulb in the socket? Just want to be on the same page

 

[da_raabi]

No, the bands are what engage the solder point on the tip to provide current.

Let me just ask this. What bulb type do people use in the courtesy light socket? 1156, 1157 etc?