is my alternator functioning correctly?

[Cruiserhead05]

In my 40 at night when its sitting there idling and i give gas the lights get brighter and the heater blows harder. when i let off they slow down. it this normal???

 

[jm]

Probably normal. At idle the alternator is not putting out all that much while the lights and blower tend to draw quite a bit... seems like most of these alternators are 35-45 amp... so they just dribble power at idle.

jm

 

[fsusteve]

Chevys are notorious for this also.

 

[CruisinGA]

Smaller alternator pulley should help this. I have yet to try it but am planning to at some point. I don't need more total output, just more at idle.

 

[73lndcrsr]

Do you have anything else on at the same time as the fan and lights? Do you have the stock alternator? Do you have a volt gauge? What does it read when you rev it up? When mine started this, my voltage regulator was going bad. I would make sure you are not getting addittional voltage from the alternator.

 

[Cruiserhead05]

i Do have 4 xtra lights and a Cd player but wether they are on or not it will still do this.

 

[CruisinGA]

First things first-
If you have a multimeter check voltage coming directly out of the alternator at idle. Tell us what it is.
Next step would be to replace your voltage regulator (is '82 external?), and replace your alt. brushes. Not very expensive and not hard or time consuming to do, and unless its been done recently, probably needs it anyway. See where you are then. Also check all your connections, and the grounds. To a certain degree, its normal for your lights to get brighter, etc when you hit the gas, but especially if this has just started, it could be a sign of short brushes, or a volt reg thats going bad.

 

[dd113]

WHat you describe is normal.Most all cruisers do it to some extent. Check the belt tension and clean all contacts. At idle with all the stuff on you should be at or just below the mid line on the amp gauge.

 

[Nadeau71]

I have a new alternator and voltage regulator and it does make the same thing as yours. no problem here!!!!

 

[FJAfrica]

Same here, put a new alternator on last week, does the same. Quite normal.

 

[roscoFJ73]

You can also check the earth lead where it bolts onto the motor.I found mine was a bit loose and the lead was corroded and needed replacement.Spraying crc/wd40 directly on to the fuse box of an older car can decrease the resistance in the electrical system.

 

[swank60]

spray WD-40 on the fuse box? Do you pull all of the fuses out first? I've never heard of anything like that before - how does it work? (I need all the help I can get with my 60)