ignition problem

[timmat1414]

1977 911 starts 98% of time, every so often it will not start (no ignition, not turning over). I do have all lights , radio, etc but no ignition. I wait and keep trying and eventually will start. Any thoughts?

[RoninLB]

I changed the electrical part of the ignition switch at 100,000 miles before it craped out.

don't rember exactly but if you pull the whole switch you should be able to test it with a meter next time the problem occurs.

[T77911S]

is there a clicking sound? if so bad solenoid. but also do as i said below, i have seen low voltage due to car alarm, storng enough to pull in solenoid but thats all.

check for 12v at solenoid. if you have 12v, the solenoid is going bad. you can fix it if you know how to solder. if so, let me know and i can step you thru it.

[ossiblue]

The posters above have you on the right track.

One of the key diagnostic signals is the "click" referred to by T77911S . If you don't hear it, the likely suspect is the switch itself. Listen carefully for it (maybe even have someone else turn the key while you are outside the car) and also note any dimming of lights (easier to detect in the dark, of course). No click and no dimming points to the switch--no flow of current. Dimming of lights points to the solenoid/starter as current is flowing but is impeded.