Remember you asked,

Inga has a 740 100 Amp alternator that cranks out 14.2 Volts through an external voltage regulator and has passed a couple of load tests with flying colors. The one positive result of blaming the charging system at first is that it's rock solid now. Every single battery cable was replaced with a brand new one, including all the ground wires. The reason for the external regular was that there was also a voltage drop on the internal regulator of the alternator if you stopped the car to fill up or run into a store. That drop in voltage showed up after a new lifetime warranty alternator was installed. It's predecessor had worn brushes. Auto Zone gives you a rebuilt unit instead of just tossing you new brushes. The heat from the exhaust manifold would heat up the regulator and cause it to drop voltage output. Hit the regulator with a shot of freeze spray and the voltage would jump right back up. I did not want to pull the alternator off again and decided to go external. The external regulator is away from all the heat and is adjustable, it does of course drop the voltage on longer drives as the battery gets fully charged. The other reason for the external regulator was to give my after market e-codes the max voltage. That was the real motive for fixing that regulator heat issue anyway.

That battery measurement mentioned in the other post was on a hotter than hell day under a full sun a few weeks back. And now that I think about it, that reading came off the VDO voltmeter inside the car. The Volvo Voltmeter (also made by VDO) in Inga used to have also has a voltage drop, Art pointed out that to the light bulb heats up the innards and causes that. A brand new VDO meter was installed along with four other VDO gauges within the last year. Get the voltage off the switched side of the ignition and do see the voltage drop on the meter. At night and during the few cooler moments we have down here, the voltmeter will read 14.1 running down the road. However when the engine is hot and so is the weather, under the hood you read 14 volts and inside the car will read as low as 13 volts. I have run down the road with a DVM hooked up to the alternator voltage so I could compare that voltage to the reading on the dash as a way to double check what the reading under the hood is vs the voltage reading inside the car. This is an 86 and there is still some of the beloved crap installation still out there under the hood and other places. Right now, don't think that is what is causing this problem.

For now with the relay installed, it's all good anyway.

Regards,

Paul