unused posts on the headlight switch on 70-72 and maybe late

[rjewkes]

i'm sure the post in the center is p for park only for the 67-69 trucks.

was wondering what a goes to? it is also without a connector in the wire harness ens? could A be used for the roof lights? with a relay in line somewhere?

[layedout72]

I wondered the same with my old harness....and was told it should have 3.

[Thunderfoot]

Yep "P" is for the front "Park" lights...
"A" is an Auxiliary and is not used for anything on our trucks… It is HOT all the time and is connected to the internal Circuit Breaker in the light switch for the Park/Running lights… With it being HOT all the time you couldn’t use it for the roof lights… This is how the roof lights are factory hooked up http://www.fordification.com/images/sch ... arkers.jpg

[layedout72]

Soo.....if we have all three prongs used, we can't have park lights? Or am I reading it wrong?

[Thunderfoot]

I'm confused there are 8 prongs on the light switch...

[rjewkes]

ahh A could be used with fog lamps with a switch in between to keep trhem off when not needed.

or for a factory spot that kills itself when folded up. And perhaps sirens on a fire company bush truck.


looks like they wire off the running light cercuit then go to the realay. for now i have them hooked in without the relay and will updat to a relay as soon as i can get it wired up right.

wqould i go with a four wire or with only a three wire/pronged relay?

edit answered it myself.

it would wire just like the relay for the upgraded headlights.

4 pronged one from the battery/sxelenoid connection.
one from the headlamp switch running light connection. and one to the lights and one to ground near by the relay for the ralay ground.