Alternator, voltage regulator, or battery?

[crashcaptn]

When I’m cruising, my dash lights are just fine, my amp gauge is in the “charge” area, and everything is great, but when I come to idle at a stoplight, I drop into the “discharge” area and my dash lights get very dim. At a stoplight when I was completely stopped I dropped it into neutral (auto trans) and it kicked it up towards the “charge” a bit more, gave me a bit more juice for the dash lamps, but still in “discharge”.

My question; should I switch the alternator to a higher amp alt rather than the stock one that is in there? Is it the voltage regulator? OR is my battery not giving me enough juice?

I’m sure if I switch all three out I’d solve the problem, but who wants to do that??

The alternator is fairly new (bout a year), the battery roughly the same (however I don’t know its ratings) and I’ve never touched the voltage regulator (it looks absolutely brand new however).

The car isn’t doing anything but not giving enough power at idle.. once I step on it, everything’s great.

 

[RedFish]

Their are a crowd of conditions that can cause that weak charging system. Dead diode in the altenater is one. Lack of continuity in bulk head connecters, fusible link and amp gauge are suspect also.
To upgrade to a isolated field and electronic regulater may not fix the problem.
Gotta start somewhere so have the altenater tested first.

 

[3404speed]

Also, the fact that the wiring is a bit undersized doesn't help. Add a better wire from the alt + terminal to the + battery terminal may help.

 

[linc]

check the ground on the voltage regulator. Make sure that the paint is scraped off the body under the mounting point. I scrape the paint off the back of the regulator (if its the epoxy encapsulated kind) and scrape the body mounting point too. Larger guage cable is good too, and some people run a ground wire from the alt to the volt reg to the battery to ensure a good ground.

 

[crashcaptn]

Good ideas, i'll go through all those. My plan on Sunday is to check the power output of the alternator and battery and move on from there. Didn’t think about checking grounds.. so I’ll go through everything. I know I’m not giving very detailed info either.. so thanks for workin with me guys

 

[3404spdvaliant]

JMO,
Upgrade the alternator to the dual field 60-66amp and switch to a electronic voltage regulator, the old one is mechanical which makes for poor transition between charging.
Be suspect of the amp gauge in those old a-body's a lot of the time they go bad [ they start flickering/jumping ] if this happens get a stewart warner amp gauge and run the wires from the old gauge to the new.

Even after these things you will still notice a lil head light dimness while stoped at intersections, I would install head light amplifier box.