Why would my battery drain faster than it can charge when using my lights and wipers

[Misstere]

We have a '61 Gmc 1500 pick-up. It runs great and we just bought a new battery for it. Driving home at night with the lights on will drain the battery quickly and using the wipers with the lights is not an option.

Can anyone tell me if it is most likely the regulator or the generator and why? Is there a way I can narrow it down?

Thanks so much for your help.

Jeannie B.
Posted via Mobile Device

[Captainfab]

Welcome to the forum

I'm not an electrical expert, but it could be either or both. Have you checked the charging current? It should be 13.8-14.2 volts. If it is not in that range, then the regulator, would be the least expensive to replace. But I can not say for certain that the generator is not the culprit. If this were my truck, I would seriously consider upgrading to an internally regulated alternator. You will have a much better electrical system.

Edit: Had a couple more ideas. Does all the wiring appear to be original and intact? All the connections look good between the generator, the regulator and the battery??

[Misstere]

Thanks CaptainFab,

I believe it is all original and all hooked up properly. I will tell my husband your advice in the morning. He intended to try the regulator first. I thought there might be a way to pinpoint it without replacing the wrong part. We want to keep it as original as possible.

Thanks again for your advice.

Jeannie
Posted via Mobile Device

[Captainfab]

I would check the voltage at the generator and at the battery with the engine running and see if it is within the 13.8-14.2 range. If the generator is in range and the battery is not, I would suspect the regulator. If the generator is not in that range, then that would likely be the culprit.

You might get a better educated answer to this question in the electrical section here on the forum. You could contact a moderator to have this thread moved over there.

[1963c-10]

Just remember to unhook the battery prior to installing the regulator. They are easy to short out.

[Misstere]

My husband thanks you both (so do I!), I told him this forum was great. I have told him he should join so I don't make us look like fools asking silly questions (nor wasting other's time). He will try the voltage test. Thanks again for helping us out.
Posted via Mobile Device

[1963c-10]

No problem. Were all here for the same goal

[BR3W CITY]

Is the truck still running original sealed beam headlights, or has it at any point been changed over the the replaceable halogen bulb style? The po of my truck converted to halogen bulbs but didn't run a headlight relay, instead coming right off the switch. Eventually this caused a short and a drain...might be something to consider if yours has ever been fiddled with.

[Misstere]

Thanks BR3W_City, they are the original sealed headlights. I appreciate your experience though.
Posted via Mobile Device

[flashed]

I would bet its the regulator . Good luck and welcome.

[jchav62]

I had a similar problem last year with my '62. THings would cut out if too many things were turned on... ie, radio, lights, wipers, etc. I'd come to a stop and everything would cut off or flicker. It ended up being my engine harness. I was lucky enough to have an extra wiring harness in the garage. I swapped it out and it's been perfect since.

This is the harness that plugs to the firewall, runs to the regulator and the horn relay, then to alternator.

[markeb01]

One other important consideration many newbies don't know about - the generator must be polarized any time the system is disconnected. Here is the applicable entry from the 1960 Chevy Truck Shop Manual:

POLARIZING THE GENERATOR

After reconnecting leads, momentarily connect a jumper lead between the "GEN" and "BAT" terminals on the regulator. This allows a momentary surge of current to flow through the generator which correctly polarizes it. Failure to do this may result in severe damage to the equipment since reversed polarity causes vibration, arcing, and burning of the relay contact points.

And welcome to the forum!

[Misstere]

Bless you all for your advice. My husband is off to check out your suggestions. If we need the generator rebuilt, we will try to find someone in south Jersey or northeastern Maryland. I know it would be easier to replace it with an alternator but we grew up working on old vehicles and we appreciate the beauty of the original. Thank you all for helping us keep a piece of history alive!
Posted via Mobile Device