Signal lights flashing very fast

Hey guys. I couldn't find a thread on this so maybe you could point me in the right direction. I just replaced the flasher unit with a new one along with a brand new turn signal switch. Good news is that I have lights that work now. However the flashers/signals are very fast on front and back.

I'm planning on replacing all my light bulbs with new anyway but I doubt that would fix the speed of the flash.

Any thoughts?

Thanks,

Eric

burnt out bulbs tend to make them go faster. Also LED bulbs do not give the necessary resistance and act the same way. If all bulbs are good and not LED I would check the flasher itself by substituting a known good unit.

Thanks Jeff. Not LED. New flasher unit installed. Old flasher had the same results. So maybe replacing all the bulbs will help. Cool. We'll see soon enough.

Thanks again

if you turn on the hazard lights do they blink just as fast as when you just use the turn signals?

the car has 2 flasher units. the hazard light flasher is next to the fuse box and the turn signal flasher is above the glove box.

if there are no LEDs in the system and both flashers are going off fast could be a possible short, most likely place is the front turn signal light buckets. you can test that by popping out the bulbs in the front one at a time and see if you get a slow down in the flashing.

that would pin point the issue.

now if the hazards are slow and the signals fast you could try swapping flashers and see if the signals slow down, that would pin point a issue with the new flasher unit.

i went through a couple flashers before i found the one i liked. there are many manufacturers and some are faster then others some are slower and some are extremely loud when they click. there are also electronic flasher conversions for leds compatibility.

just note: do you have an LED conversion in the instrument lights in the dash.

having LEDs in the turn signal flashers also changes the amp load and can speed up the flashing. so even if you do not have leds on the external lights you have to consider the internal lights.

flashers are usually bimetal that heats up and cools down making the lights flash on and off, a change in the load reducing heat will effect the flashing depending on the make of the flasher this can result in a speed up or slow down. some flashers are NC (normal closed) and some are NO (normal open) so for example a lower load on a NC will cause it to speed up but the same load on a NO will make it slow down.

Electricity is fun!

If you don't find a problem, switch to a heavy duty flasher, they aren't affected as much by variances in the bulbs or wiring. Most people have the opposite problem with our cars, slow flashers caused by corroded connections.

Thanks guys. No LED that I know of. Fairly certain of that but this is a new car to me. I looked for a flasher under the glove box but didn't find anything there of note. I will look again. I changed the flasher under the steering column. Heavy duty flasher may be a good bet. Hazards flash fast also I think but will verify.

Good advice all,

Thanks again,

Eric

The other flasher is above the glovebox just above the relay plate.

I have a similar problem in that my turn indicators also flash very fast - I would say 180 times per minute.

- I do not have any LEDs anywhere

- All bulbs seem to flash brightly - I don;t think I have a bad earth or blown/weak bulb

- When I turn on my hazard warning lights, all four turn lights come on and stay on - i.e. they do not flash at all

My conclusion is that I have a failed hazard light flasher units (the one next to the fuse box) and that needs to be replaced and that is causing the turn signals to flash fast.

Do you agree my diagnosis ? Thanks for any and all input as ever guys.

Make sense to me. Your in the Detroit area. NPD in Canton has them in stock for 2.95. Here is the link.

https://www.npdlink.com/store/products/mustang_flasher_turn_signal_or_emergency_flasher-101687-443.html

John J

I agree with the faulty hazard flasher. Remove the hazard flasher and try the turn signals again and see if they operate normally. I tried looking at the schematics and have a theory and removing the Hazard flasher should make the turn signal light operate correctly and confirm that that hazard flasher is faulty. If that works I can explain why the turn signals were flashing so fast. I am curious to know the results.

I agree with the faulty hazard flasher. Remove the hazard flasher and try the turn signals again and see if they operate normally. I tried looking at the schematics and have a theory and removing the Hazard flasher should make the turn signal light operate correctly and confirm that that hazard flasher is faulty. If that works I can explain why the turn signals were flashing so fast. I am curious to know the results.

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Hmmmm! I took a look last night at the area around the fuses where the flasher unit for the hazard lights should be and..... couldn't find it! I'll take another look today and will also pull out my wiring diagram but I suspect the flasher unit may be missing and this is why the hazard lights stay on and don;t flash when turned on, and why the turn signals flash fast.

Ummm...if the flasher is not installed, nothing will blink or even turn on when you turn on that particular circuit: turn signal or e-flasher.

The E-flasher unit on my car is located in the glove box. Its on the left top rear corner. The turn signal is on the right side of glove box above the relay plate. Just a note that my relays were wrapped with a grey insulating tape from the factory, probably to insulate them from shorting somewhere.

could have 2 issues here the flasher module as you noted is missing and, try this; Pull the bulbs from the front turn signals and retest. 71-72 under the front bumper, 73 on the grill.

the front turn signal sockets are notorious for being rusted out and cross shorting internally causing all kinds of turn signal and hazard light weirdness.

Just a note here, with my e-flasher removed the turn signals still work.