{Chrysler 300} PITA voltage problem

Well,

I suspect that this problem has been going on over the last month as I started driving the 300K but since I do not have a voltmeter on the car, I did not notice. Once off idle it starts to ramp up way past 14 volts.

I purchased one of those $10 USB things that plug into the cigar lighter. This one has a voltmeter built into it. That is when I noticed the overcharging the other day.

We spent a couple of hours trouble shooting. What is going on is that the wire from the starter switch through the bulkhead connector, then on to the voltage regulator is showing a Â½ volt drop. We checked the resistance on the circuit, and it is not showing any issues. We even jumped the spades with the connector off of the starter switch and we get the same result.

What is happening is the reference voltage on the voltage regulator is 11.5 volts. That is causing the VR to tell the alternator to crank up and we end up getting 15 to 18 volts on the system.

What is interesting is the “orange box” of the ignition is placing enough load on the circuit to cause the issue. If we disconnect it that loss to about an 1/8 of a volt. It still should be 12 volts, or the VR reference will not be correct.

I have never had such a problem. I need to figure out how to deal with it. I suspect that if one was running points, it would not be an issue with the small loss of reference. But then again who knows as this car is new to me and it could have been cooking batteries for a long time.

Anyone ever run into this? I cannot conceive of this being related to the Power Master alternator.

My neighbor who used to work in auto electric work thinks the way to deal with it is to place a relay next to the VR to make sure it is getting its reference voltage at 12 volts and not rely on the dash wiring to supply it. Since at some point I may go to EFI, I will need a clean 12-volt source under a load that is switched in any event.

The only other option is to open up the entire wiring harness under the dash and replace the wire from the starter switch through the bulkhead connector up to the ballast resistor then on to the voltage regulator with a new wire.

I do not have the kind of tester to check the wire under a load to see if it is the section from the starter to the bulkhead, the bulkhead to the ballast resistor or from there to the VR.

Tired and going to get a drink.

James