blinky headlights

[71 LONG BED]

My headlights have the ever so popular blinky problem. Only after a long enough time for a "warm up" of the circuits.
I was just reading up on the wiring diagram page and saw this;

If the total load on either headlamp circuit breaker exceeds the breaker rating, the headlamps or taillamps will cycle on and off indicating the overload. If this occurs, a portion of the added lights must be wired through a relay, feeding the relay coil from the headlamp switch.

Is it possible the relay is bad? I'll also have to check to see if there is anything wired into the headlight circuit, although I don't believe there is. Also, if I reach under the dash and feel the switch after it has begun blinking, it does feel a kinda warm. Any other ideas?

I have poked around enough to learn my roof markers aren't factory. They seem to be FoMoCo lights. Maybe installed at the dealer? That explains why they don't have the factory spacing.

[bluef250]

The headlights have circuit breaker that wears out. A relay allows power to bypass the switch and the breaker. The switch activates the relay which in turns powers the lights. The relay circuit is an add on. The top lights should be on their own circuit.

[71PA_Highboy]

No, the relay can't be bad, if it were there would be no roof lights and no overload.
The easiest way to do this is disconnect the rooof lights... if the headlights stay on, the you need a relay for the roof lights... if they still blink the problem is elsewhere...

HTH,

Eric

[71 LONG BED]

No, the relay can't be bad, if it were there would be no roof lights and no overload.
The easiest way to do this is disconnect the rooof lights... if the headlights stay on, the you need a relay for the roof lights... if they still blink the problem is elsewhere...

HTH,

Eric

Sorry for the confusion, I threw the comment on the roof lights in there as an extra thought. They aren't wired to the headlights. If they were wired into the headlight circuit they would only come on when the headlights were on, which is not the case. They do come on when the only the driving lights are turned on.

[ima71 trucks are older]

Everytime I've had the blinking headlight problem on a ford, its been the headlight switch. bumpsides and dentsides, always the switch.

[fordman]

your new switch could have been bad or something sorted it out when you turned it on.

[TheEskimo]

Long shot, but I had a bad wire on my passenger side tail light that caused a similar problem, I am still in the process of replacing them old wires as I get the time to do it.

[Thunderfoot]

Don't know if you seen this wire diagram or not for the clearance / cab lights... http://www.fordification.com/images/sch ... arkers.jpg it shows the relay and circuit breaker for these clearance lights... I haven't seen a circuit breaker for the headlights in any of the diagrams yet...

[ima71 trucks are older]

Don't know if you seen this wire diagram or not for the clearance / cab lights... http://www.fordification.com/images/sch ... arkers.jpg it shows the relay and circuit breaker for these clearance lights... I haven't seen a circuit breaker for the headlights in any of the diagrams yet...

The ciruit breaker for the headlights is part of the headlight switch.

[Thunderfoot]

Don't know if you seen this wire diagram or not for the clearance / cab lights... http://www.fordification.com/images/sch ... arkers.jpg it shows the relay and circuit breaker for these clearance lights... I haven't seen a circuit breaker for the headlights in any of the diagrams yet...

The circuit breaker for the headlights is part of the headlight switch.

I wasn't putting 2 and 2 together when I looked at the switch diagram... Thanks for pointing that out

Yep it has one for the running lights and one for the head lights...

For those that want to know, here is the symbol for a circuit breaker in the diagrams...

[rjewkes]

where would you get a relay for add on cab lights?

can i use a relay like the ones for fog lamps?

[bigdog50]

I'm not understanding what you are saying the solution is for the blinky headlights. I have replaced the bulbs, the headlight switch and the dimmer switch.