Coil Voltage

[finestjammy]

Hi All

I replaced my coil recently, old Bosch for a new Bosch. Now unless I'm doing something really stupid the voltage is reading no more than 2v. The car seems to be running fine though.

So can someone confirm if I am being stupid or not please?

I assume if it was actualy only 2v it would be running rough as a dog and would probably not start?

Thanks

James

[paulathome]

How are you measuring the voltage?
I assume your trying to measure the output voltage from the coil, which using a multimeter will be impossible. For one the meter will not be capable of measuring 20KV and secondly the voltage is such a short pulse the meter will not have a chance to react to it if it doesn't distroy it in the measurement process.
You can measure it using a spark gap device which is a very rough and ready indicator.
But if your car runs fine then it probably is working fine.
There are other ways of fairly accurately measuring the peak voltage but you would need an oscilloscope
and the skill to use it.
If your measuring the input voltage the same rules apply in that the pulse on the primary is of a very short duration to fire the coil and your meter wil not be able to measure it unless it has a peak hold funtion on it. All the meter is roughly reading is the average voltage, again an oscilloscope is your friend for an accurate reading
Paul.

Edited by paulathome on Tuesday 9th August 22:17

[finestjammy]

Thanks Paul. I don't think I'm measuring it correctly. I assumed it would be reading 12v at the terminals using a multimeter. It all seems to be fine, I was just curious really. Thanks again.