1968 Electrical problem when I press brakes, lights go off & on

[Batgirl89]

what headlights should I have/get?

 

[Batgirl89]

Neil, 15.2v at + post at idle with lites on

 

[franklinair]

15.2 is good, if not a little high. Lose the halogens. Get regular sealed beam headlights. The extra current draw of the halogens may be the cause of your problem. (Hope they didn't already harm the headlight switch.)

Neil

 

[CougarCJ]

My wholesale autoparts supplier doesn't carry non-halogen headlamps for the Cougars or 1969 Mustangs. These are the 4 bulb systems, which are slightly smaller than found on 1968 Ford Mustangs. I forget the bulb numbers, check your packaging.

Not sure that Sylvania, Wagner, etc, offer non-halogen sealed beam bulbs for older cars.

 

[franklinair]

NAPA P/N 6014, high-low beam. $5.00+/-.

Neil

 

[Batgirl89]

I sanded and tightened battery cables/posts. no change

I do have the engine block ground strap, looks original, cracks & missing in insulation, do I need to replace it? I did sand the firewall connection.

located the flasher for the turn signal

cant seem to find the emergency light flasher, even while upside down, face pressed against the brake pedal, I almost got stuck...I was so wedged in.

Ill change the headlights out next, if that doesnt do it I should replace the headlight switch right?

 

[franklinair]

Please confirm:
Battery negative cable grounded on engine block?
Ground strap between firewall and engine?

Something to try:
It may be a PITA to get to, but unplug both headlites. Then see if problem re-occurs. (Headlite switch on, engine @ idle)

Neil

 

[Batgirl89]

Please confirm:
Battery negative cable grounded on engine block?
Ground strap between firewall and engine?

Something to try:
It may be a PITA to get to, but unplug both headlites. Then see if problem re-occurs. (Headlite switch on, engine @ idle)

Neil

good idea! ill try it.

negative battery cable is grounded to the block on the water pump/alternator bracket. I was wondering should I move it to the bolt on the side of the block instead?

I have a ground strap from firewall to engine, its old

 

[Batgirl89]

I took the headlights out: no change

can I get a headlight switch from Napa? or should I order one?

here is a (bad) pic of the neg battery cable mounting. should I change it to the side of the block?

 

[franklinair]

CougarCJ (WestCoastClassicCougar) can get you the switch. ($50+/-)
I'd put the ground cable on the side of the block- only because that's where its supposed to be. Electricly, its a moot point.

Neil

 

[Batgirl89]

could this be a ground issue or something with the brake pedal switch?

 

[aemoo28]

Relay switch. Every time I hit the brake pedal, the dash lights would flicker then go dark, then my brake lights failed. Rob knows what this is all about.

 

[aemoo28]

could this be a ground issue or something with the brake pedal switch?

Yes. Involves removing the driver's seat and getting to the area under the steering wheel. Something about the new halogen lights sucking too much current or something. Don't remember what the suggestion was- think it was the headlamps that shorted out the circuit.

Nearly had a rear ending one day however the nice man in back of me relayed that my brake lights were not working and how he'd hate to plow into the back of my pretty car with his Ford F150.

We FORD people stick together, don't we?

 

[franklinair]

Amazon.com
AC Delco 6014 sealed beam headlight $8.40

Neil

 

[Batgirl89]

aemoo28 we do stick together! so do you have halogens? Ill ask Rob what he did

ok so, Rob what relay switch??

 

[Ruppstang]

I have Halogens in our 68 fastback and have driven it thousands of miles all over the country and the lights have never gone out once. I would put in a new heavy duty switch and I bet you will be fine. Unless there is some resistance wiring issue. Marty

 

[Mosesatm]

Another headlight issue culprit can be the dimmer switch, especially if water has been dripping on it from a leaky cowl or windshield.

 

[franklinair]

Early posts on this subject say no headlight malfunction. Only dash lights, side marker lights, and tail lights. These are a different circuit from the headlight circuit, thru the headlight switch. Power for these lights don't appear to go thru the brake light switch or turn signal switch.
My wiring diagram leaves me a little in the dark, as far as wire # 984-which I assume is a ground circuit, and #57 appears to be power.
Once the basic power supply has been verified (Ground, Power) for the 12V system of the car, the common denominator for the affected circuits appears to be the headlight switch.

Neil

 

[Batgirl89]

Another headlight issue culprit can be the dimmer switch, especially if water has been dripping on it from a leaky cowl or windshield.

i was thinking about the dimmer switch too, but the headlights have been fine, and yes the windshield has been leaking with all this rain (how did you know) we need to build another garage, we have too many ponies and not enough stalls. My husband wants the horses gone so we can convert the barn! but I did make room in the hay barn for a couple of the ponies

 

[Batgirl89]

Early posts on this subject say no headlight malfunction. Only dash lights, side marker lights, and tail lights. These are a different circuit from the headlight circuit, thru the headlight switch. Power for these lights don't appear to go thru the brake light switch or turn signal switch.
My wiring diagram leaves me a little in the dark, as far as wire # 984-which I assume is a ground circuit, and #57 appears to be power.
Once the basic power supply has been verified (Ground, Power) for the 12V system of the car, the common denominator for the affected circuits appears to be the headlight switch.

Neil

thank you for getting into the wiring diagram, I get lost! I think im best to start with the headlight switch