96SR5Limited

alright.... i installed my blue bulbs and my clear bumper turn signals on my 96... i got the left one on and everything it works fine... i put my right one on .... and it doesn't work.... when i turn the signal on in the car..... it blinks SUPER fast.... but up front it doesn't blink or ne thing... in the back it blinks REALLY fast... i cant figure out why it won't work......? even the arrow on the dash blinks sooooooo fast... need some help?

midiwall

It sounds like the right front bulb may be shorted.

The "blink" comes from a device that's up under the dash which depends on heat to open and close a circuit. It's what's known as a thermocouple. As current flows through the device (the "blinker"), heat is generated, when there's enough heat, the thermocouple opens and breaks the circuit. With no current flow, the tempurature comes down, thus letting the thermocouple close again, and the light comes back on.

The process is repeated until you turn off the turn signal. The rate of the blink comes from how much current is flowing, which determines how much time is required to heat up the thermocouple and open the circuit.

If the front blinker bulb is shorted, then the resistance in the circuit is less which will cause more currrent to flow. With more current flowing through the thermocouple, it will heat up faster and give you a higher blink rate.


What happens if you swap the left and right bulb? If the problem moves with the bulb, then the bulb is bad and I'd return the one that doesn't light up. If the problem stays on the right side of the truck, then the socket wiring has gotten mashed and you need to check that out.


Mark

96SR5Limited

hmmmm..... alright then .... who can fix this problem?

TDiddy

You can! Like Mark said, try switching the bulbs from side to side. If you switch them and then the left side blinks real fast, then the bulb is bad. I'd guess that its about an 85% chance that its just the bulb.

96SR5Limited

alright lets pray ill find out tomorrow

TDiddy

Be sure to let us know how it work out for ya!

Good luck -

Robinhood150

Is it really called a thermocouple? Usually a thermocouple is a device used to measure temperature. Just about every electronic thermometer you see uses a thermocouple.

I'm just curious and it's more for my information.

Steve

midiwall

Hmmm... I think you're right Steve. I've always known a "heat activated switch" in its simplest form as a thermocouple, but now in hunting around the net, I can't find anything to back that up.

I find references to metals which have thermocouple properties being used like this, so maybe someone simplified it down to that point eons ago for me and it's just stuck.

TDiddy

Here's what I found on thermocouples from this link :

Thermocouples are among the easiest temperature sensors to use and obtain and are widely used in science and industry. They are based on the Seebeck effect that occurs in electrical conductors that experience a temperature gradient along their length.

Thermocouples are pairs of dissimilar metal wires joined at least at one end, which generate a net thermoelectric voltage between the the open pair according to the size of the temperature difference between the ends, the relative Seebeck coefficient of the wire pair and the uniformity of the wire-pair relative Seebeck coefficient.

Robinhood150

I've always called a mechanical temperature sensitive switch a "bi-metallic switch", like a thermostat in your house (well, an old house).

FYI,
The way it works is that two dissimilar strips of metal are bonded back to back. When the temperature changes each metal expands at a different rate and the bi-metallic strip bends and makes contact or breaks contact.

Basically, what Tom quoted is that two dissimilar wires are welded together at one end. When any two dissimilar metals touch they produce an electical charge, a voltage. A device measures this voltage and the voltage changes with temperature change.

Yes, I'm a nerd.

Steve

midiwall

Got it!

Thanks Steve, Thanks Tom!


96SR5: Did you figure out if it's the bulb or the socket?

CTB

Ya you are Steve...

But it's cool to be one. I wish I was when it came to electrical stuff.

96SR5Limited

well today ill finally check into my none working blinker... ill inform u guys when i get home and find out whats wrong with it

96SR5Limited

well when i got home from school... it wasn't the bulb... it was a bad connector or something.... its hard to explain but i guess the stock one went....? cause the clears i bought came with extra connector... connectors being a word for the thing im talking bout that i have no clue whats its called... its the part that another part slides into that connects the wires to the bulb or something well its all up and working....thanks

TDiddy

Well whatever that was, glad it was easy to fix and you're back in business!