Electrical problem has me stumped! (56 Coupe)

[Brent Bliven]

Happy Fourth of July everyone!

I have a unique electrical problem on my 1956 Hardtop Coupe that I would greatly appreciate any advice on solving.  

The symptom seems straightforward enough: when the headlights are turned on they come on fine for about 15 seconds and then both flicker (wiring to lamps appears to be fine).

My thought was a faulty generator.  I checked the output of the generator with the battery disconnected and it was putting out in the 12v range apparently with no problem.

What really has me stumped is that while the battery is disconnected, and the car running, if I turn the headlights on, it immediately shuts the engine down as surely as if the headlamp switch was an off switch to the engine.

Might the voltage regulator be the problem?

Thanks for any advice.
Brent

[Bruce Reynolds # 18992]

Gday Brent,

I wouldnt be surprised if the internal circuit breaker in the headlight switch is sensing a short somewhere in the headlight system and is cycling through the on-off process that allows someone with a headlight fault at night to still have some form of illumination to be able to stop safely.

This may be intermittently causing a problem that shuts the ignition down as wel with the battery removed.

Bruce,
The Tassie Devil(le),
60 CDV

[wm Link]

 you might have a bad ground. Be sure that the small black wire near your headlamps is screwed to the core support properly. Remove the screw and clean the area. Make sure that you have the large braided strap that is bolted to the starter mount to the frame...often people do not reattach them. Disconnecting the battery cable while the engine is running is NOT recommended, the battery could explode from the spark that is made...it is also effective in damaging your charging system. Recheck your battery and headlamp connections, remove, inspect and clean all of them. Hope that is of help to you!

[wm Link]

Also...CHECK YOUR FLOOR DIMMER SWITCH!!!! Ill bet thats where your problem is.

[Warren Rauch]

  Does the car have automatic headlight control?  Warren

[George]

You dont say how the problem started. Did it just start happen or did you have any work done on the car.
 Does the ignition light go off when your engine stalls.If it does the fault is in the wiring circuit from the light switch.
  Disconnect the headlamps at the back of the units, and see if the same thing happens when you operate the switch. If the car still stalls then it is not current draw from the lamps. Some electrical components can cause drag on the generator, enough to stall an engine. Your headlamps could be the fault.
 
 Disconnect the two live wires ( main and dim) out of the dimmer switch, and try using the switch without the headlamp wiring. Note what happens when you operate the switch.  
   
Replace the cables one at a time and note the reaction. If the engine stalls when the wires are disconnected then the problem is not in the wiring from the dimmer switch to headlamp. but is in the light switch circuit somewhere.
 
If the engine does stall with either wire reconnected then the fault is in that particular circuit. Main or dip.
  Disconnect the battery wiring from the generator,including the ground. try the headlamp switch again. If the engine stalls this will rule out the genny or control box.
  If the engine does not stall with the charging system
disconnected, then the charging system is at fault.
Hope this helps.