Fast Blinking...

[Nigel215]

I just installed new LED's in my DRL's, Turn Signals, and Parking Lights. They are all working, but when I hit the turn signal they all blink really fast on that side...even in the tail lights. But when I put on the 4 ways (hazzard lights) they blink at the regular speed. To my knowledge , when they are blinking fast it means that one of the bulbs is out, but they are all working. Im a little confused. Anyone know whay it would be doing this?

[silveradoman]

You don´t use the same relay for the emergency flashers, I believe the turn signal relay is supposed to do that, it needs to be heated up by the current going through the system to interrupt the flow of current for a little while and when it cools it lights up again. When a bulb goes out, you don´t get the same current through the circuit, so it flashes faster to let you know the bulb is out. With a plain light bulb you probably have 3 amps going through the circuit, with a LED you may have depending on the amount of leds on the "bulb" only abuot 0.6 amps, so the flasher thinks a bulb is out. This is great as far as leaving your parking lights on all night and you won´t drain the battery. See if your turn relays are thermal or thermic, there might be a different type of relay in an autopart store. I know in the past the turn signal was controlled with a thermal flasher relay, I would think by now they would have put an electronically timed circuit in there but you never know with GM

[broughy84]

I would say that you are going to have to add an inline resistor to make them work correctly. I'm not sure how many ohms you would need though.....Hope you can find a good wiring diagram.

[silveradoman]

put an amp meter in series with the light bulb you just took out and plug it directly to the battery, measure the amps, 12V=(amps) X (bulb internal resistance), so divide the 12 volts by the reading on the meter to give you the resistor value you need.

[gschretter]

The new turn signal lamps draw a whole lot more power. Causing more heat faster.

There a two different kinds of relays.

One is therm (mech) and the other is timed or something.

You have a termal relay.

The other kind cost more but they slow the turn signal down.

Also the termal one will probably burn out really fast.

if you keep the turn signal as they are today people will think you have those fancy germany turn signals.

[Mikado14]

gschretter is correct, the multiple LED replacement lights draw more current than a single filament bulb. If you go to your local parts store, you will want what they call an electronic flasher. It has the same pin configuration as the thermal but will have a smoke clear cover. You will be able to look inside and see some circuitry and a relay. This type is not dependent on current flow like the bimetallic or thermal type.

We use these on tractor trailer or semi's and a lot of them are using the multiple LED lights.

[silveradoman]

Í don´t see how even 20 LEDs would draw more current than an incandescent bulb, LEDs give off no heat and use 20miliamps each, is this some kind of new LED?

[cs1]

Originally Posted by silveradoman

Í don´t see how even 20 LEDs would draw more current than an incandescent bulb, LEDs give off no heat and use 20miliamps each, is this some kind of new LED?

I was thinking the same thing.

[gschretter]

20 LEDs pull a lot more amps than normal light.

How they use the engery is different.

Use an amp meter and find out.

[silveradoman]

Well, did something better, took out the calculator. Lets assume you have 20 LEDs; 2.1 volts, 20mA and 42.6mW of power, this gives you and internal resistance of 105 ohms. If you put 20 LEDs in series, you have 20 X 105ohms = 2.1 kohm. Knowing this, we get 12v=(I) X 2100 so your current in series is 0.0057 amps, so in a series setup, you won´t get any light out of them.
Now lets assume a parallel setup, the sum of the inverse of the resistors would equal 5.25 ohms, if you have 12 volts in your system then you get a current of 2.28 amps. OK, so you get light with a parallel setup, you are basically using 27.5 watts on this LED cluster. How many watts does the incandescent lamp use? less than 27? hope my high school teacher isn´t turning over in his grave because I didn´t do this before I opened my mouth, oh well....

[Nigel215]

I donno if their some new led or what. i just got them off e-bay (im officially addicted) their are 12 led's on each bulb, and the little corner bulbes have 4 on their faces.

[Mikado14]

Originally Posted by silveradoman

Í don´t see how even 20 LEDs would draw more current than an incandescent bulb, LEDs give off no heat and use 20miliamps each, is this some kind of new LED?

An LED will not emit any light until the threshold voltage of 1.5V (app) is reached. It will provide maximum light at approximately 2.5 to 3V and should not exceed that. Current draw at threshold will vary from 20mA to 100mA max and some of the Jumbo LED's are nothing more than parallel LED's in the same housing and they will draw more than a single LED.

In a replacement light with LED's, it is constructed with series-parallel LED's. I have seen some replacements LED lamps that draw more and some that draw less. The advantage to using these is the brightness that can be acheived.

One thing should be corrected here and I don't know who posted but with a thermal breaker, flashing a front bulb and a rear bulb, the current causes the bimetallic to heat and expand thus breaking the circuit. When it cools, it makes contact and the process repeats. If one bulb goes out, the flasher will slow down since less current is being used and not heating the bimetallic as quickly. Thus, if your flasher is flashing slow, you most likely have a bulb out.

If your flasher's flash rate has increased, you are pulling more current. You have your answer, the LED lamps are drawing more current. Go to an Auto Parts store and purchase an electronic flasher, they are not dependent on current flow to establish the flash rate.