no headlights, no turn signal, need help please....

[bigred72]

So here's the deal, my blinkers and headlights have been working just fine until tonight, now nothing . checked the fuses and all looked good. park lights come on front and rear. is there something that controls both blinkers and headlights. BTW its a 72 f100 4x4 w/ a 4spd. Your help is greatly appreciated. thanks.

[fordman]

the headlight switch get power and then sends it out to the dimmer switch. then onto the the headligths. then a retunr from the headlights goes to the turn signal switch. or some routign like that. since the turn signal switch and the headlights are both bad. i would say you turn signal switch (tss) is bad. here are the diagrams. http://www.fordification.com/tech/wirin ... _quick.jpg

[Thunderfoot]

park lights come on front and rear. is there something that controls both blinkers and headlights.

If your park lights work then you have power to the light switch so your problem is more then likely in the headlight dimmer switch on the floor, try messing with it a bit first. If that doesn't work it could be the headlight switch itself, as the circuit breaker in it might have died. Do you have a test light or voltage meter to do some testing with? If so I can give you more specific wires to check.

is there something that controls both blinkers and headlights.

No, they are separate circuits from each other, no inner connection... You may have two separate problems.
Something else I would check is the ground strap on the firewall to engine and make sure it is making good contact, bad grounds can do strange things.

[bigred72]

Thanks for the help guys. Got it figured out. Turns out it was a bad dimmer switch(good call Thunderfoot). Still not sure what caused the blinkers to stop working but got them working too. when it rains it pours i guess.