Hi 'cropharvester' thanks for the reply. Any chance you could list the specs of the electronic flasher? Reason being, the specs on the flasher I installed are: 20A, 2-terminal, 1-10 Lamp Load, 12V, electronic flasher and the problem did not go away. BUT when I take the bulbs out of my truck, the trailer blinks normally. I expected the new flasher to solve the problem but it did not.

 

does the trailer have LED taillights? if so there is not enough current draw for the ecm in the truck. it thinks that a light is burnt out and kicks into fast flash mode

EDIT

DUH did not read the 1980 F100 part. Never mind my post!

 

An electronic flasher should blink the same speed regardless of the number of bulbs, LED or incandescent.

Have you tried a different bulb where you take the one out (that causes it to behave)?

 

dont have any info on the electronic flasher,think I got it at napa dealer in 1989,sure cured that fast blink problem,lasted 20 years then sold truck.

 

If your signals blinking too fast, you gonna need drain the signal line and add Prestone Heavy Duty Signal Fluid.



















Just kidding. HaHa. When I got my '94 F150 13 years ago, it does that, look under the steering wheel dash, there a fuse box, I believe it's big round fuse, You gonna need get different one that can handle trailer wiring. I replace it and my signals blink normal when hooked on trailer wires. Sorry I can't remember the name of it but I remember it was big round fuse in fuse box.

 

Hey Folks,

Thanks for the ideas, so here is some more information:

1. I replaced the existing flasher with an HD flasher, this did not do the trick.

2. When I removed the truck signal bulbs the trailer lights blink at normal speed - I ended up doing this to get the trailer inspected.

3. I checked the trailer and truck bulbs are the same, non-LED bulbs. I replaced them all for good measure but they still blink fast.

Now that the trailer has passed inspection I am not as panicked about this problem but it would be nice if the the lights blinked at normal speed with the trailer hooked up. I suppose I could install a separate flasher, split the wiring between the two flashers, and wire the trailer feed to the new flasher if I was so inclined. But for that trouble I will probably just let it blink fast.

If you have any additional ideas I would be happy to hear them.

Thanks!

 

I bought an enclosed trailer years ago & had that blinker problem. Ford dealer parts guy sold me a "variable" flasher that worked correctly with or without the trailer.

 

Hi CS,

Thanks for your help here. I did find a variable flasher online, produced by Grote. I gave their applications engineer a call - he recommended I try changing to LED lights on the trailer & truck in order to reduce the amount of amps running through the flasher, with the idea being that the reduced current draw would return the flasher back to 'normal' speed while double loaded.

I am not sure when/if I will get around to this - I want the blinkers running at normal speed but at least they will still serve the function of a turn signal even though they are running fast with the trailer. I would hate to convert to LEDs without knowing for sure that they will solve the problem.