1980F-1504x4 Light probs head,tail,parking,blinkers,dash. please help!!

[gargoyle]

I've got a 1980 F-150 4x4 351M. I can't figure out the light's!!!
First I had headlight but no taillight's yet I had parking light's.
Bad wire's by tail light's so I replaced them.
Now headlights come on and go off when ever they want for how ever long they want.
Plus if headlight are on left blinker will not blink just stay's on. Unless heater blower is turned on then left blinker will work.
Also when I would step on the brakes the dashboard lights up as well as the heaters dash light's when headlight switch was NOT pulled out to on position.

So I replaced the headlight switch behide the dashboard. Now I have these problems............
Headlight's work fine. NO parking light's. NO dashlight's. Blinker's work now.

But if I Step on brake pedal the brake light's work and only then will the dashlight's work. All fuses are good.
So I've fixed the headlight's and the blinker's but now have no dash light's or parking light's.
I need help on this one. Could it be that the headlight switch is a 1982 instead of a 1980?? I can't see the diffrents between two years.
I'm going nut's here!

[Winddrifter]

Sounds like you may have a couple of wires shorted together. YOu may have to open up the wire harness and spread out the wires to find the chafe.
BUT first.... Check the grounds at the brake lights and park lights. If you had a bad ground on the brake lights system it is possible that the current for the brakes is finding its path to ground through the park lights system. Sounds wierd but I have actually seen something similar to this a while back on one of our old farm trucks.
Good luck,
Windy

[gargoyle]

Thank you windy, However I have a conformation from a friend who work's at a ford plant that it is in fact my headlight switch. The switch I replaced mine with was a 1982 and he said I have to replace it with a 1980. I wish he was easyer to get a hold of, I could have done this in the first place! I too thought it was a bad ground somewhere with the wire's, but he seems to disagree.