Noticed a month or so ago (Jan 2019) on a night drive that headlights and dash lights were modulating (varying intensity).
Then looked at Digital VM plugged into Cig Lighter Outlet and saw voltage varying from 13.6VDC to 14.8VDC (varies up and down in increments about 0.2 volts). Normally, when voltage is steady, I see 13.7 V +/- a little.
The problem of varying voltage comes and goes (intermittent) and seems to not be there when car is first started. Then shows up later (sometimes drive as far as 7 miles before I see it).
The last day or so (March 1 and 2 of 2019) I did some trouble shooting after searching on Internet for Voltage Regulation problems for Dodge and or Caravan, There are plenty of problems - some have changed Alternator, PCM (Computer), Battery, or Whatever.
Apparenly a common problem as there is a company that provides a KIT to install an external Voltage Regulator. Thus, bypassing the PCM regulation. I think sometime around 1980s or early 1990, Dodge eliminated the External Voltage Regulators by using the PCM to control the Field Coil current on the Alternator (thus changing the output of the alternator).
To make a long story short (it is all ready long).
I have made some measurements at the coil connector and see about 3 VDC on the BR/GR Wire when Accessories or OFF and about 5.3 VDC when the Accessories or ON. It is a steady voltage when the output is steady 13.7VDC at Idle speed.
However, when the out put is varying (13.6 to 14.8VDC) the BR/GR wire voltage is all over the place (3.6VDC to 0.0VDC to OL - Overload display on my Digital Voltmeter).
My Opinion is it is the PCM failing to regulate the voltage (putting out wrong voltage to the Field Coil). That said, it could be something in the alternator (brushes, slip ring, diodes,), or a bad connection but I don;t think it is anything but the PCM.
I might add - in all the searching I did, never saw a problem like mine (varying voltage and intermittent) - most were complete failures of some sort and some had replaced everything (PCM, Alternator). And some installed an External Regulator essentially bypassing that part of the PCM function.
PS: My 2205 is a low mileage and not driven much anymore (last 7 years we have had a different car that became primary car and I use the MC or that car) I use the VAN for short trips, errands, and as sort of a truck as rear seats are out of it and sometimes camp a few nights in it while on a Camp and Ride MC trip to another state).
A D V E R T I S E M E N T S
Noticed a month or so ago (Jan 2019) on a night drive that headlights and dash lights were modulating (varying intensity).
Then looked at Digital VM plugged into Cig Lighter Outlet and saw voltage varying from 13.6VDC to 14.8VDC (varies up and down in increments about 0.2 volts). Normally, when voltage is steady, I see 13.7 V +/- a little.
The problem of varying voltage comes and goes (intermittent) and seems to not be there when car is first started. Then shows up later (sometimes drive as far as 7 miles before I see it).
The last day or so (March 1 and 2 of 2019) I did some trouble shooting after searching on Internet for Voltage Regulation problems for Dodge and or Caravan, There are plenty of problems - some have changed Alternator, PCM (Computer), Battery, or Whatever.
Apparenly a common problem as there is a company that provides a KIT to install an external Voltage Regulator. Thus, bypassing the PCM regulation. I think sometime around 1980s or early 1990, Dodge eliminated the External Voltage Regulators by using the PCM to control the Field Coil current on the Alternator (thus changing the output of the alternator).
To make a long story short (it is all ready long).
I have made some measurements at the coil connector and see about 3 VDC on the BR/GR Wire when Accessories or OFF and about 5.3 VDC when the Accessories or ON. It is a steady voltage when the output is steady 13.7VDC at Idle speed.
However, when the out put is varying (13.6 to 14.8VDC) the BR/GR wire voltage is all over the place (3.6VDC to 0.0VDC to OL - Overload display on my Digital Voltmeter).
My Opinion is it is the PCM failing to regulate the voltage (putting out wrong voltage to the Field Coil). That said, it could be something in the alternator (brushes, slip ring, diodes,), or a bad connection but I don;t think it is anything but the PCM.
I might add - in all the searching I did, never saw a problem like mine (varying voltage and intermittent) - most were complete failures of some sort and some had replaced everything (PCM, Alternator). And some installed an External Regulator essentially bypassing that part of the PCM function.
PS: My 2205 is a low mileage and not driven much anymore (last 7 years we have had a different car that became primary car and I use the MC or that car) I use the VAN for short trips, errands, and as sort of a truck as rear seats are out of it and sometimes camp a few nights in it while on a Camp and Ride MC trip to another state).
- Paul M., Sevierville, TN, US