Pulsing in Lights and Bouncing in Battery Gauge ---

[Bill C.]

Can anyone shed some light on what is making this happen?

I can see the lights get bright then dim and there is a bounce in the gauge.

If I kick the RPM up over 1500 then it seems to subside. It is also much more noticable when I have the headlamps turned on.

It charges just fine - no issue with that at all, the gauge does not peg way over in any one direction, just has a bounce (to the + side).

Any direction for a cure is appreciated.

[Kim C.]

Re: Pulsing in Lights and Bouncing in Battery Gauge ---

I would guess that the internal voltage regulator is failing. I would verify that the battery, alternator, and ground connections are good first (the wiring, not the actuial part). Then have the alternator tested. Many auto parts chain stores will do it for free. Of course, if you need to maintain originality, then acquiring the proper rebuild parts is next. Good luck!

[Kurt G.]

Re: Pulsing in Lights and Bouncing in Battery Gauge ---

As mentioned above, check the alternator, connections and the regulator. One other thing to check, the battery. All too often the battery is the last thing to be checked. Several things to check, the first being how old is it, and the brand. I've got to get on my horse here, so bear with me. During the 80's and 90's I had the pleasure of having the avocation of professional bass fishing, and also owned an electric trolling motor repair business, as well as being sponsored by a major battery manufacturer. It amazed me how many guys out there would spend $50K on a boat and buy their batteries at Wally World for $49.96.

Back on topic. Seriously, batteries today are better than they were when our cars were built, but not by much. In the 20+ years that my livelyhood depended on battery power, I, and a lot of other guys learned that a good battery is very valuable, and can be the root of many mysterious problems. Pull the battery out and take it, uncharged to a reputable battery distributor for testing under load. Your flickering problem may very well be a weak battery, that is boosted to dependability when your alternator starts putting out about 30 amps to run the car.

Good luck.

[Bill C.]

Re: Pulsing in Lights and Bouncing in Battery Gauge ---

The battery is maybe 1.5 years old - it is a Restoration Battery R89W.
No issues with it.

As for the alternator - it has a new diode pack, regulator and brushes, all installed about 2 years ago.

I going try taking out the plug at the alternator and cleaning the contacts and the prongs.

I am hoping it is not a gauge issue.

Are there any voltage/continuity checks I can run with the VOM to troubleshoot?

[Kurt G.]

Re: Pulsing in Lights and Bouncing in Battery Gauge ---

Bill. I wish I had a dollar for everytime I heard "it's a new battery" when I had the trolling motor repair business. Without exception, when I'd run the motor on my test bench all was great, and I'd hear back about a week later, or less, they guy bought a new battery and the problem was gone. It's an easy check, cost nothing, and could possibly save you many hours of hair pulling. It could also be as simple as a bad connection on the battery. Use a little petroleum jelly or contact compound on the connections and see it that helps.

[Rich P.]

Re: Pulsing in Lights and Bouncing in Battery Gauge ---

Bill,

I have to agree with Kurt on this. I recomend for all my customers who plan to drive thier car to get a top brand battery and only use the restoation batterty for judging. I would remove the restoration battery and put it on a shelf with a self regulating trickle charger and spend the money on a top of the line battery. I have seen lots of cars with either ignition or lighting gremlins caused by a "marginal" battery.

Rich

[Kurt G.]

Re: Pulsing in Lights and Bouncing in Battery Gauge ---

Bill, to add to Rich's post, a top of the line battery, translated based on my extensive batter experience, means AC Delco. Don't buy any other brand. They may not make them themselves anymore, but they still have the highest quality specs for their vendors. Time to go fly airplanes for a week.

Good luck.

Kurt

[Edward J.]

Re: Pulsing in Lights and Bouncing in Battery Gauge ---

Can anyone shed some light on what is making this happen?

I can see the lights get bright then dim and there is a bounce in the gauge.

If I kick the RPM up over 1500 then it seems to subside. It is also much more noticable when I have the headlamps turned on.

It charges just fine - no issue with that at all, the gauge does not peg way over in any one direction, just has a bounce (to the + side).

Any direction for a cure is appreciated.

Bill, have you checked the basics belt tension on the alt. also look for a glazed belt( shiny surface).also look at neg. battery connections at rear frame. and battery connections at battery. if all these look good I would be looking at internal alt. problem, maybe a rectifer bridge or diode trio.

Bill one more item, standing battery voltage should be 12.66 that is a fully charged battery, Car running 13.8-14.2 volts,these test you can use a volt meter. this is not a complete test for the charging system but a health check.

[Jack H.]

Re: Pulsing in Lights and Bouncing in Battery Gauge ---

A rather common issue is the electrical contact integrity of the 2-conductor plug on the engine harness wire that inserts into the side of the alternator. One conductor is the 'sense' wire (what is the condition of the battery?) while the other is the field winding power.

I've seen general contact cleanliness problems here as well as harness wire to plug contact fatigue fracture. Bottom line, if both of these conductors aren't ROCK SOLID, expect all kinds of 'funnies' in terms of your charging systems' output integrity.

[Bill C.]

Re: Pulsing in Lights and Bouncing in Battery Gauge ---

turned out being the connectors in the plug.

I cleaned them up, tightened them a little too - issues went away.

Thanks for all the suggestions.