I'd had that exact same problem, although mine was only one side so I didn't change the switch or I probably would have too.

 

Hi all,

my first post ever and probably the first to post from Ireland.

I have the exact same problem.
Parklights ok
Full Light ok
Headlight not ok
I'm convinced it's not the light switch, because the full light works.
And it does only do that when the switch is in the 2nd (fully out) position.
So it's either the cabling, the lamps or what you discussed here. the harness connector.

Could you please help me in locating where these 2 harnesses go together ? than I'll give it the same try.
Seems to be a common 65 Model problem.

it's raining out here at the moment (typical) but as it stops i'll check if there's + and - coming to the headlamps from the cable to isolate further

Thanks in advance. Have attached a picture from my 1964 1/2 mustang. I believe it's the only built in 64 driving around in ireland.


[IMG]local://upfiles/52145/0F07C25E1E5B43889A7E1264BDF5BAB6.jpg[/IMG]

 

Great news !

i got it fixed as well. i found the connector (i don't know what this is called) at the firewall ?
cleaned and fit to go again.

I checked on the wiring diagram and came up with the folowing:
if your full lights work and the headlights don't (or the other way round) then this is proof that the lightswitch is not the problem.

As mentioned before
a) if you are in the first pull of the **** then parking lights come on. if you are in the 2nd then the head or full lights come on. (so never at the same time at a 65 model)
b) the light switch in 2nd pull will power a cable +12V (red/yellow). this goes to the pedal (full light switch).
c) depending on this pedal switch either red/black gets +12V (headlight) or green/black gets+12V (full light)

so as mentioned before, if full light works then you have power on red/yellow, which means your switch is fine.

This all valid for 1964 1/2, but my guess is the same is for the later models as well that use this pedal swith.
The headlamp has 2 wires for low and highbeam. and only 1 of them can be burning at a time (heat)

Hope it helps for the next lad or lassie with the same problems ....

Kalli

 

welcome, and it's great to see mustangs from around the world!

 

For whats its worth, as I see you have fixed your problem, my problem ended up being the 3 wire pigtail to the dimmer switch. All of my symptoms were exactly the same.

[IMG]local://upfiles/52472/A3C55CF41E984DD08D7AABF6189D28E4.jpg[/IMG]

 

good
just wanted to be sure noone with the same problem (headlights work full lights don't or other way round) ever comes up with the idea againof changing the headlight switch

Kalli