I had a battery die on me few weeks ago, i put it on the charger and now its fine, all charged up at 12.76 volts. BUT i turn the key and nothing, wont turn over, lights wont go on either. When i bypass the positive terminal to the relay, the engine turns fine with power.

what can i check? bad ignition switch? is there a fuse below for the ignition?

 

anyone?

 

Well, it's the middle of a warm, sunny afternoon here, so probably few visitors to the forum.

If you use a small jump wire from the battery (+) to the solenoid (S) the starter should engage. If it does, but the starter switch will not engage the starter, check the wiring first, especially the connections between the (+) terminal on the solenoid, the firewall plug, and the plug on the back of the ignition switch. There is no fuse in this circuit.

 

Could be the solenoid, when mine went out it gave constant juice instead of none, even with the ignition off the car was trying to start. Installed a new solenoid - fixed. Maybe you fried the solenoid if the ign. was left on too long. You could always use a test light to see where the juice stops, start at the batt. and work to the solenoid.
Jon

 

Just went through this on my 65. The plug at the firewall in the engine compartment had come unplugged. On my 65 it was on the drivers side just below the hood hinge. I could jump the solenoid and the car would crank. No lights, horn or ignition. Plugged it back in and she was good to go.

Here's the thread from September. Lot of good info on this problem.
https://mustangforums.com/forum/clas...al-system.html

 

Hiya Cyprus,

since you have an automatic I'd check on the neutral safety switch first

 

I messed around with wires unplugging and plugging to make sure everything was ok and they all looked fine. I checked batt juice and its ok at 12.72volts. Now ive jumped the positive terminal of batt to starter relay and the engine turns over fine.

I then put the key in and turned ignition switch and the radio went on, as soon as I went to put the lights on i heard a PLINK and everything went dead. Now it continues not to have lights radio or nothing. No response. What was that PLINK noise?

 

Could it be a voltage regulator?
Have you checked to make sure the clamps are clean between them and the posts and are tightened up. A loose dirty clamp can arch out and make everything appear dead. Old cable wires can also fail.

 

your pretty spot on. i checked the wires and the main lead from the relay to the voltage reg/alternator is toast and was grounding itself against the actualy voltage reg making a dead connection.

any ideas where i could upgrade the harness, voltage reg and perhaps even a new relay since im at it?