Hi there!

I have a 1979 f-250 4wd that I just replaced the wiring from the engine to the rear ( lights, fuel tank, etc. ). Anyway, all works great and is a text book hook up. The only thing in my way now is the turn signal switch which is worn, and when moved in certain spots, either the right or left brake light turns off. So I figure there is a bad connection in the turn signal switch.

Well... now for the prob at hand.... and it may be related, may not be. I am just looking for someone that may have encountered this.
I bought the adaptor made for my model Ford where I place this in between the rear light 4 conductor connection block, and it supllies wires for a trailer. All connections and soldered and solid. Ground seems... seems to be good.
When I test the lights on the trailer, everything works. Its just the turn signals go into hyperdrive. Half as bright and twice as fast. It only affects the turn signals.
Unlpugging the trailer from the 6 pin connector lets it go back to normal blinking on the truck.... plug it back in... the truck and trailer blink irradically. I tested the trailer once more on my other car and all is well. I am assuming there is a prob with the truck somewhere.

Could it be a lost ground somewhere? Do I need a bigger blinker relay? Or is it just that dag-gone turn signal switch... in which I am saving my $100 for a new one.

Any help will help.

Thanks!!!

 

If I'm following correctly, I had two Fords do the same thing-both times I replaced flasher with a heavy duty flasher and problem solved.

 

I agree.
A flasher is made up inside by two contacts. One is fixed (doesn't move), and the other is made of bimetallic material (two different metal strips bonded together). One of the metals bends further than the other at a given temperature; so the strip heats up when the signal light is on and "bends" away from the fixed contact (opening the circuit and turning off the light until it cools).

Adding lights (like trailer signals or roll bars with turn lights) causes the flasher to use more current (elecrtriciy), thus it gets hotter quicker (and cools more often). this gives the "rapid flashing syndrome" you are experiencing.

More lights, faster flashing (until burnout of flasher or fuse, of course).

OldFords

 

OK when you move the turn signal switch to the right the right brake light doesnt work and to the left the left brake light doesnt work, this is the way Ford designed it. The switch still maybe worn though if you are moving the switch and the turn signals arent on but the brake light is out. So I guess you can replace the switch or just not move the turn signal switch until you want to use it

Sparky

ps
The others are correct you need a heavy duty flasher unit when you hook up more lights to the system.

 

Excellent!!! I will give a bigger flasher a try. Makes sense.

When I move the turn signal lever slightly before it locks in place, the entire rear light goes out. Drove me nuts for hours trying to find the short, jigling wires, etc. ( the light was not working at the time ), but yet, each time I jiggled the wire harness up above the brake light switch in the peddle, it would flicker on and off... so I knew it was up front. Never occured that leaning on the turn signal switch lever was doing that. HA!!!

So far, problem solved.


I will give a bigger flasher a try. Thanks~!!

You all are awesome!!

 

There is one drawback to the heavy-duty flasher, but it is unavoidable. With the original flasher, if you have a problem with one of the bulbs in the system, the flasher would not flash, giving you an indication something is wrong. The heavy-duty flasher will just keep on flashing regardless if bulbs are out or not, so you have to inspect your outside lamps once in awhile to make sure they are still working after you install the heavy-duty flasher.