Hello:
I am new here, and I thank you all for your help, in advance.

I have a 1966 Mustang convt, 289, and the car has never let me down in 15 years. Today, I drove it a bit, and as soon as I turned the lights on, the car died, and I lost all electric power. I checked the battery, and it is fine, even hooked it up to a charger. No lights, no radio and nothing when the ignition is turned.

The only place I have power, is to the convertible top, so I was able to put that up.

Any thoughts?

Your help is appreciated.

Thanks

Viraf

 

I am no expert but I would check the ground to the engine. Here is a quick way to check, Hook up a jumper cable to neg terminal on battery then to engine block & see if anything comes back to life. It may not start but it may click or something & point you in right direction. Hope it helps

 

Very wierd - went out and noticed the interior cabin lights came on - so I was able to start her up and get the car back in the garage. Once in, I tried the lights again, and once again, the car died. Tried the negative direct to the engine with no response.

Could there be a short in the headlight switch that is causing an issue?

Any other ideas? Thanks again

Viraf

 

That is a strange one. I would agree with your assesment of the head light switch. I don't know why it would do that but they are not that expensive and not that hard to replace. It is worth a shot.

 

Its a strange one - it is fine with the parking lights on, and only dies with the headlights. Then it sits for 15 - 20 minutes and fires right up. Everything works incl the radio, brake lights etc.

 

My first inclination would be to check your light switch foran internal short. Next, I'd check each running light, front and back, and make sure you don't have a short in one of the lights. Before you go replacing parts and digging into your wiring, I'd do a walk around to see if any hazard lights, or running lights are either burned out, or illuminated differently then the rest, it's quick, simple and doesn't cost anything.

 

by the way, when was the last time you had your alternator checked. You might be running on your battery, and not know it. By turning on your lights, you might have just enough voltage drop to cause ignition failure. Thought I'd toss that out there, another option. Sorry, us old guys are full of cobwebs....

 

+1

I'm gonna guess that you're Alt. is failing. It's not common for a light switch to short out and cause total electrical failure. Possible, just not probable.

Have your alt checked. Or, do it oyur self. Get the car running and puta meter on it. If you're pusing 14 volts, then you're ok. If the batter stays at 12v and slowly leaks down, then your alt is not charging.

 

Thanks Guys - I will try and do some troubleshooting.

Just wondering - if it is the alternator, and the car is dying because when the lights turn on it sucks the juice out of the battery, why would it not atleast try and start up right after? I mean, it makes no sound if I try to start it up right after it dies. Once it sits for 15 - 20 minutes it starts right up. Does that make any sense???

Thanks for all your help.

Viraf

 

Yes, it makes sense. The battery builds back up just enough amps to turn the engine over after 20 minutes or so. Take your car to an auto parts place with the lights off, and have them check the battery, alternator and the voltage regulator. One of those three parts has failed.