Charging problem solved? Loose ammeter wire(s).

Posted by Mark Buckley On 2012/6/7 14:27:17

Starting eight months ago my 1950 Standard Eight has seen:

Three 6-volt batteries (two replacements, both brand new)
Three generators (two replacements, both completely rebuilt)
Five voltage regulators (four brand new replacements)
Two fan belts (one brand new replacement)

These items were installed by professional mechanics, who thoroughly checked them out at the time of install.

Previous to all this I had the car completely, and professionally, re-wired with original-looking harnesses and cables I bought from by Rhode Island Wiring. Several times over the past few months I've had the car's wiring inspected (by professionals) for poor grounds. Every inspection has turned up nothing.

No matter what I did or had replaced, it seemed, the current flow in the car never seemed adequate to keep up with the demand--particularly if I was driving at night with the headlights on and had to come to a stop. Almost invariably, the car would stall while just sitting there or when it was time to go again. Often, I had to kill the lights to get enough juice to restart.

Yesterday I left the car, again, with a specialty auto electric shop here in Seattle. After some hours I got a call: the car was ready for me to pick up.

On arrival at the shop the mechanic told me the following:

The wires to the ammeter in the instrument cluster had come partially loose. To me, it had looked like the ammeter was working well. But he noticed the wiring to and from the meter was dodgy. He had managed to tighten the wires and this improved the current flow to the point where the charging system was functioning properly. Apparently, all power produced by the system had to pass through the ammeter. If the power could not pass freely through the meter, it would starve the system.

The mechanic went on to say this is one reason why ammeters were replaced by volt meters.

I drove the car for awhile (in daylight) with the lights on, and it generally seemed better.

I have no idea whether this "loose wires at the ammeter" is a common or uncommon problem, but I just thought I'd share it with this group. I've spent well above than $2,000 on all this electrical stuff and I find it ironic that the problem may have been a simple loose wire!

Al the best,

Mark