Volt meter at coil terminals

-
3

340 swinger

Well-Known Member
Joined
Apr 29, 2007
Messages
206
Reaction score
0
I am not really up on DC electrics but just for fun I checked the pos and neg terminals at the coil while idling and it only registered 7.2 volts. I have 14.6 at the alternator and similiar at the battery. This car is running mopar performance electronic ingition and orange box with accel coil. Am I mistaken in thinking that there should be 12v at the coil?
 
If the ballast is bypassed, your wiring connections are very bad. How positive are you it's bypassed?
 
moper said:
If the ballast is bypassed, your wiring connections are very bad. How positive are you it's bypassed?
Click to expand...

The connectors are pulled out of the resistor and is jumped from one side to the other.
 
340 swinger said:
I am not really up on DC electrics but just for fun I checked the pos and neg terminals at the coil while idling and it only registered 7.2 volts. I have 14.6 at the alternator and similiar at the battery. This car is running mopar performance electronic ingition and orange box with accel coil. Am I mistaken in thinking that there should be 12v at the coil?
Click to expand...

Neg. lead of your meter on ground? If you have the neg. lead on coil neg and pos lead on coil pos. all you are measuring is voltage drop across the coil. Neg meter lead on ground and pos meter lead on coil pos should show close to system volts(if your resistor is bypassed) neg side of coil may show 1/2 system volts(being pulled to ground 50% of the time by the module) BTW I don't think you should by-pass the res. w/ Mopar electronic ignition.
 
The Holley installation manual instructs you not to use the coil to power the choke. After the vehicle its started you will have only 7-8 volts at the coil.
HKeller
 
You should not have the ballast resistor by-passed. You will be running the coil hot and shorten it's lefe expectancy.
 
dgc333 said:
You should not have the ballast resistor by-passed. You will be running the coil hot and shorten it's lefe expectancy.
Click to expand...

Yes,not only will the coil get hot,the poor transistor(coil driver) in the ECU was not meant to carry that type of current for extended periods of time. That driver has to switch on and off every 90* of crank revolution!!
 
green1 said:
get a new resister, fast.
Click to expand...

Well today I bought a new ballist resistor and installed it this evening. When installed it operates just like a resistor that is no good. Car starts and stalls every time. So I am guessing I have something else wrong. Any input?
 
There are two power circuits to the ballast through the igntion key. They atre called IGN1 and IGN2. IGN1 provides power to the upstream side of the ballast when the key is in the run position. IGN2 is attached to the down stream (coil side) of the ballast it provides power directly to the coil during cranking (i.e. the ballast is by-passed) to aid starting. When one is on the other is off.

From what you describe it sounds like there is no power being applied to the up stream side of the ballast when the key is in the run position. Eseentially what you have is you turn the key to the crank position and it starts so you let the key go and it returns to IGN1 position and there is no power so the engine suts down.

Get your voltmeter out and start tracking down your problem. Could be bad wiring, bad ignition switch or even a blown fuse.
 
You must log in or register to reply here.
-

Back
Top