county 4bd1 overcharging.

[Gavo]

Has anyone had an overcharging problem on a county.
The car had a old style regulator on it which was replaced with an Ingram replacement one, one of the control coils in the regulator was open circuit.

The auto elec suggested it was the alternator or the battery. I have swapped the alternator out of my 4bd1 with this one with no change.
It still over charges up to 15.5 volts with higher rpm. I have also swapped the battery as well.
I have also tried the regulator out of mine as well with no change, they were the same part number.
Now when it over charges the charge light pulses bright red and 15.5 volts at the battery.
I have noticed that my stage one 4bdi and my county 4bd1 have both had the wiring modified. The stage 1 has a relay that is switched from on ignition source, providing direct battery feed to two of the terminals on the regulator. My county has a lead with a fuse going from the battery connection point on the alternator to one terminal on the regulator.
This problem seem to come and go, but over time drains the battery down to eventual have slow cranking.

It never happens at the auto electricians workshop.

Any help would be good.

[JDNSW]

I had an overcharging problem once about ten years ago after it was standing for three months, corrected itself after about ten minutes running, but there was no warning light on, just the voltmeter off scale.

For any alternator to overcharge it must be either a fault with the regulator or a wiring problem stopping the regulator from working correctly.

As you point out, this alternator has a separate regulator, which does introduce the possibility of a wiring problem external to the regulator or alternator. Since the regulator senses the voltage between the battery and the chassis, if the regulator has a faulty earth, this means the regulator will see the battery voltage as less than it really is, and will increase the voltage to the field.
So my guess is a faulty earth on the regulator (obviously intermittent). This could be external to the regulator, or internal. And it could be the earth between the engine and chassis - which could also be the reason for the "slow cranking", or even between the body and chassis.

John

[Larns]

I had an overcharging problem once about ten years ago after it was standing for three months, corrected itself after about ten minutes running, but there was no warning light on, just the voltmeter off scale.

For any alternator to overcharge it must be either a fault with the regulator or a wiring problem stopping the regulator from working correctly.

As you point out, this alternator has a separate regulator, which does introduce the possibility of a wiring problem external to the regulator or alternator. Since the regulator senses the voltage between the battery and the chassis, if the regulator has a faulty earth, this means the regulator will see the battery voltage as less than it really is, and will increase the voltage to the field.
So my guess is a faulty earth on the regulator (obviously intermittent). This could be external to the regulator, or internal. And it could be the earth between the engine and chassis - which could also be the reason for the "slow cranking", or even between the body and chassis.

John

Agree, 99% of all elec problems are poor connection/earth.

[Gavo]

The ignition feed/battery sense terminal at the regulator was around 1 volt lower than the battery indicated, there must have been a power loss through the wiring some ware.
So my thinking was that the regulator would have been getting a false indication of the battery voltage.
I installed a relay to direct alternator power directly from the charge terminal an the alternator to the regulator.
When I tested the voltage at the same terminal afterwords the reading was the same as the battery.
I also noticed the the erratic voltage fluctuations had gone also.