Lights going bright then dim then bright

I seldom drive my 1981 308 at night. But,the few times that I have,I notice that my lights-all of them- Headlights and dash lights- will be a certain level then,all of a sudden,get a surge of power and get really bright,then back down to "Regular" again. (Fluctuate)

It usually occurs mostly on acceleration,or deceleration. But,also can occur just at cruising speed.

Almost looks like I'm flashing my brights,on and off...

Any suggestions? I did install a brand new "Optima" Battery in it. And installed all new fuses. But,the car has only 19K miles on it. I bought it a little over 3 years ago with 14K miles on it. And,I found the original owner who bought it new in 1981 and sold it in 1995 with under 3K miles on it. So,obviously,the car did alot of sitting...

So,I'm thinking that I should clean all of the connections that I can get too. But,what else should I be looking for...? I cannot get to every connection on the car. Does the Alternator sound like it may need repair?

Also,after driving it for quite awhile,it stops the Fluctuating....????(Sometimes. It Depends on how long I am out driving)

Could it just be something as simple as the battery is charging,and once it's completely charged,it stops? I do drive the car somewhat frequently during the week,but not a whole lot.And,when I don't,It is plugged into a "Trickle Charger".

Any help is much appreciated! Thanks!

Frank,

This sould be a fairly straight forward problem to troubleshoot...with two likely areas of concerns: The alternator itself, or the wiring (connections) directly between the battery and the charging system.

Starting at the front on the car, I would remove and clean:

-The positive battery cable to main harness connector
-The negative battery cable to battery connector
-The negative cable to ground connector (near the battery)
-The chassis ground to engine cables connections points
-The alternator to bracket mounting strap connections
-The positive lead from the main harness to alternator B+ post
-(If the car is equipped with a battery cut-off switch, verify that those connections are clean and tight)
-Verify that the alternator belt is not slipping

If you find all of these connectors clean and tight, have the alternator load tested on the car. Based on your description of the problem, I'd suspect an internal problem with the alternator. Any competent alternator shop can handle the rebuild for around $100, or so. The alternator used is a "nothing special" 55/65 amp Bosch unit, as found on many Fiat models of that era...

Regards,
David

Thanks for your tips. Yes,I was going to get at every connection that I can,and clean and check them. As I mentioned,the car sat alot in its first 24 years. Then,every Winter since. That always causes some extra Corrosion on the connections.

Yes,I noticed the Bosch Alternator. I am fortunate to have a Bosch Service Center close by. If things don't get better after I do some cleaning,I'll pull it out and bring it over there for them to check out.

But,It still runs when you disconnect a cable,so I was assuming that it was O.K....?

Frank,
They should be able to test it in the car...that should save you some work.