1/2V Drop on Ignition 1 When VR Is Pluged In Normal?

[Moparfiend]

1970 Satellite with SBM with shorted (Brown/Blue/Blue*) ballast for MSD ignition. I am working to install a Progression Distributor requiring a good ignition switched 12V source.

Vbatt=12.6V

Measuring the node of ignition 1 (Brown and Blue and Blue*) with the Voltage Regulator disconnected I get 12.6V VBatt no drop.

But when I connect the Voltage Regulator I measure 11.9V a 1/2V drop.

Is this normal?

 

[451Mopar]

really an indication of bad electrical connections, likely at the bulkhead connector.

 

[Mopars & Missiles]

really an indication of bad electrical connections, likely at the bulkhead connector.

Or internal to the ignition switch........

 

[Moparfiend]

The detected 1/4 Voltage drop only occurs when the VR is plugged in….. The blue/brown/blue trace lines already connected together. When the VR is plugged in that node drops from 12.6V to 11.8V.

 

[451Mopar]

A work around if you don't want to fix the actual problem is to just feed the regulator battery voltage through a relay activated by the existing voltage regulator power wire. Use a fuse in the relay power circuit just incase it every shorts.

 

[Moparfiend]

A work around if you don't want to fix the actual problem is to just feed the regulator battery voltage through a relay activated by the existing voltage regulator power wire. Use a fuse in the relay power circuit just incase it every shorts.

I did that today actually. Now I can get the car running and probe around to see if there is actually any issues.

 

[RJRENTON]

The detected 1/4 Voltage drop only occurs when the VR is plugged in….. The blue/brown/blue trace lines already connected together. When the VR is plugged in that node drops from 12.6V to 11.8V.

The electronic voltage regulator has an INTERNAL VOLTAGE DIVIDER network (a series combination of resistors) that is used to measure the battery voltage an thru this voltage divider combination, turns on/off the NPN transistor that controls the alternator's rotating field voltage and the alternators output voltage....the maximum current is determined by the stator's impedance and diode capacity. This internal voltage divider network presents a small overall voltage drop when the regulator is plugged into the harness. This is a NORMAL occurance. It is likely that nothing is wrong with the system......just my opinion of course.....
BOB RENTON

 

[Moparfiend]

The electronic voltage regulator has an INTERNAL VOLTAGE DIVIDER network (a series combination of resistors) that is used to measure the battery voltage an thru this voltage divider combination, turns on/off the NPN transistor that controls the alternator's rotating field voltage and the alternators output voltage....the maximum current is determined by the stator's impedance and diode capacity. This internal voltage divider network presents a small overall voltage drop when the regulator is plugged into the harness. This is a NORMAL occurance. It is likely that nothing is wrong with the system......just my opinion of course.....
BOB RENTON

Thanks Bob for the reply!