What Would Cause a Turn Signal To Flash Quickly?
 

I just noticed in the last week and a half that both the left and right turn signal lights and associated dash indicaters blink really fast when activated. They used to blink maybe a couple times a second. Now they blink maybe 3 or 4 times a second. Does that indicate that the flasher can on the fuse block is nearing the end of it's life cycle? Nothing has changed on the truck. No new or special bulbs were installed.

its the flasher. my hazzard lights look almost like they are staying on they flash so fast, if i take tha flasher off my turn signals and put it on the hazzards they flash normal.

hmmm..Good idea. I haven't tried moving the hazard flasher for testing..sounds easy enough to fix. Guess I'll make a trek to the autoparts store for a new flasher. Hopefully it's only a couple buck fix.

I had a similar problem with mine except they would flash normal, then fast, cycling back and forth. I swapped the hazard and turn signal flashers and now they both work just fine.

Some times when you have a bulb out it causes it to flash faster like that. So you know that its out. But is strange that both sides would do it at the same time. Just my 2 cents.

jason
77 f100

i with the guy above me

Too much current draw will cause the quicker flashing.

That's why when you plug trailer lights (more draw) in on a vehicle with a standard flasher installed , one must replace it with a Heavy Duty Flasher. HD-12

Too little current will cause it too. They put a circuit in the flasher so that you can tell if you have a burnt out turn signal. I had to modify the fenders on my 99 TJ and only used two of the 4 turn signal lamps, and this caused the quick flash, installing LEDs will cause it too. If this really starts to get to you look up TJ turn signals + LEDs and you should be able to find a link to site that will tell you how to fix the flasher. I'm sure that the flashers should be pretty much the same. But since you didn't do anything to your lights your best bet is to check and make sure all your turn signals work and nothing is messed up w/ your wiring.

With the Ford TS circuit, if a light filament is damaged, the lights WON'T Flash.The indicator light will just stay on...no blinking.

The GM circuit is the one that lets one bulb flash.

I can't see how a lower draw would cause the flash to increase.

Higher Current draw causes the seperation of the Flasher circuit sooner, That's why when you add Trailer lights the current draw is larger.... causing the bi-metal strip in the flasher to seperate quicker.
A HD flasher has a higher seperation rate than the light duty flasher thus blinks slower with the increased load..

Forgot to mention that all the bulbs worked, just flashed fast, then slow, then fast.....has worked fine ever since I swapped flashers.

Some HD flashers have a third pin for ground so they flash independent of the load.

sorry I didn't realize that ford had a different set-up though I should have. I was speaking from experience on my JEEP. There is a seperate circuit INSIDE the flasher that monitors the current draw. If it is not within the preset range (either high OR LOW) it will flash faster.

The bi-metal tab in the flasher heats up faster anytime the current increases. This causes the flaser speed to increase when hooking up a trailer. I am with dennis I'm not sure how a missing or burn't out bulb could cause the thing to speed up, but anything is possible.

As far as the LED conversion is concerned, the flasher will usually stop completely because the current is so low that the bi-metal tab cannot heat up. There is a solid state flasher that is available to cure this problem. They have been used on RV's for years and can be found in most RV supply houses.

I once replaced the stock rear signals on my motorcycle with smaller lights. The flash was very fast. I needed a resistor in the circuit to get it back to normal flashing speed.

My truck is a Trailer Special, and uses heavy duty flasher relays, mounted under the hood near the ignition module. You can actually hear them click when they are on. Designed to handle a lot of extra light load.
Mark

its not done through a bimetal tab. Its done through a shunt resistor and internal comparator.......I don't know a whole lot about electronics so I only sorta understand but if you are really interested in it http://www.atmel.com/dyn/resources/p...ts/doc4727.pdf explains how this type of flasher works.....pin 7 in the lamp out detector. And tringot the resistor is one of the ways to fix the problem but its not usually prefered because the resistor can get really hot