Would 12.1 volts at the battery and 11.7 volts at the coil, cause engine to run rough

[greaseyfingers]

Shouldn't the voltage at the coil test the same voltage as it is at the battery?

Would this difference in the voltage, as mentioned, cause the engine to run rough on a 1987 Ranger with a 2.9 engine?

What most likely, do think, would be causing this difference in voltage, maybe, a weak ignition switch?

Also, shouldn't a good battery test around 12.5 volts, or so?

This battery has plenty of power for starting the Ranger.

So, it should have enough power for powering the coil and the engine's electrical system, too, shouldn't it?

 

[97fordrunner]

so thats the power when its running or off? And are you talking the Solenoid on the fender?

 

[greaseyfingers]

so thats the power when its running or off? And are you talking the Solenoid on the fender?

The volts on the battery, from post to post, tested 12.1 volts with the ignition switch off, while the engine wasn't running.

The terminal right on the coil tested 11.7 volts with the ignition switch on, without the engine running?

When the engine was running, the voltage right on the coil terminal tested around 14.4 volts, I think is what it indicated.

I didn't test the volts at the solenoid.