Packard Forum Index » V-8 (1955-56)

Friends,

The Executive has developed another anomaly. The Generator/Charge light glows steady after 5-10 mi driving when the engine gets warmed up, no matter what speed I am at or how hard the generator (should) be turning. It has left me with one dead battery, easily recharged. When it is cold, it is fine (red at idle, out as soon as you hit the gas).
I note that the problem appears to be affected during the warm-up process by shifting of gears and/or major road bumps; the light may flicker all the way on or off.
I find no bare wires in inspection of the primary ignition circuit; the coil seems hot to me, but it may just be engine heat. Belt tensions are normal; when cold the car starts on the button every time, with no pumping the accelerator. Could a bad coil cause full battery discharge on the road? Any and all relevant commentary appreciated.

Thanks,

JER

I would have the generator and regulator looked at. The brushes could be marginal as well as contacts or grounds in the regulator. It sounds as if heat is making something expand and lose contact so no charging.

The light is in the circuit between the regulator Bat and Gen terminals. Battery supplies a voltage on one side and the generator provides the ground thru it's windings. This allows the bulb to light until the generators voltage out on that "ground" side is equal to the voltage supplied by the battery on the other. Anytime the generator out voltage drops below battery voltage, light will glow to some extent--more voltage difference, brighter the light.

The place that rebuild my generator said the regulator could take 5-10 minutes to warm up and start charging fully...perhaps when your regular warms up it takes it out of whack?

That was a good thought about checking for loose or bare wires. You probably have a bad voltage reg.

It should not take any time to warm up and the gen should work the same hot or cold. Both cases sound like regulator problems although there is an outside chance it is the generator.

Easily checked to see if the regulator is at fault. Ground the Field terminal of the generator. If the light goes out, the regulator is at fault. If the light stays on then it could be either regulator or generator. Do not run the generator with the field grounded for any more time than to do the check.

(o{I}o)

I agree Rusty. A generator needing 5-10 minutes to warm up before reaching full output? Another of these baseless myths that seems to perpetuate itself.

A points type regulator DOES need some time to warm up, but it only should affect the voltage set point by a few tenths of a volt. (ie. such as 7.0V cold, 7.3V hot on a 6V system).The generator should charge some whenever the eng is running.

If anything, a cold generator usually can produce a few more amps of current than a hot unit (resistance increases/ amperage decreases as the unit heats up)