Ignition voltage

[AmadeusCharger500]

Can someone give me a quick review of what wires should have voltage with key on?

I had a car sit for 3 months snowed in this winter. I tried starting it and its not firing. Starter works though!

[Nacho-RT74]

recently floated on a trhead with diagrams ilustrating that. but on a fast response:

Key in RUN... Blue wire on ballast, reg and alt field, 12 volts... Coil brown wire 5 to 9 volts

Key in Start... Backwards voltage... plus the yellow wire triggering the starter relay ( 12 volts )

[AmadeusCharger500]

Thanks Nacho, I actually still have some of your diagrams from years ago but not this specific version.

I'm getting 12 volts on blue wire at ballast and reg.
No voltage at coil and no voltage to the distributor wires.

[cudaken]

 
Is there voltage on both sides of the ballast?

Ken

[Nacho-RT74]

that points out to damaged ballast resistor. Or damaged brown wire.

do you have the Brake Light dimming on cluster when cranking ? or does turn off ?

[AmadeusCharger500]

Voltage to blue side of ballast but not the opposing side. Its a 4 pin.  I will look for that brake light today.

[Nacho-RT74]

brake light is straight sourced from ign switch just in RUN, but when cranking, the brown wire is the one what feeds the circuit. Since this circuit arrives to ballast, and blue circuit is also attached to it, the brake light gets the power coming from ballast so will keep light on but dimmed.

the ECU also gets the power while cranking dimmed from ballast coming from brown circuit, but enough to keep on. So that's why a damaged Ballast will cut the power on that moment. The ballast works like a splice to power everywhere, dimmed or not. That's why I tell the brake light on cluster is a good pilot light to check if is in working order or not

Everything points out to that.

Amazing how many times I heard about damaged ballast in forums... I never have got any of my ballasts damaged in 15 years!!

[AmadeusCharger500]

Its been so long since i bought a ballast resistor.

Are they even still available in parts stores?
I seem to remember there are better quality and worse.

[Nacho-RT74]

I guess they are!!! they are down here at least. Not everywhere but neither so weird

[AmadeusCharger500]

Installed new ballast, fired right up!

Nacho I was thinking about what you said, not ever having to change one.
I'm wondering if it has something to do with climate, or changes in such. I haven't changed one for at least 5 years, and just this year we had an unusually cold winter.
Anyway just a thought.

[cudaken]

Installed new ballast, fired right up!

Nacho I was thinking about what you said, not ever having to change one.
I'm wondering if it has something to do with climate, or changes in such. I haven't changed one for at least 5 years, and just this year we had an unusually cold winter.
Anyway just a thought.

They just go bad, poor quality or just because they can?  I all wise carry a spare one. Over the last 41 years, I have replaced around 20 Not on the same Mopar mind you, I bet 7 on my 68 Road Runner.   

Cuda Ken

[Nacho-RT74]

I have never took care to carry one on trunk, because actually never have needed in 14 years as told... but if neded all I need to do is jump the ballast in an emergency and done. ( what I always have is small pieces of wire around )

of course, just for emergency to ride around up to the parts store.