Dimming lights...bright lights...dimming...bright...

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matthon

matthon

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I just replaced all of the wiring in my car, including everything that goes with that- light bulbs, H4 headlights, flasher, upgraded voltage regulator, alternator, etc. I even grounded all the dash lights separately, which made them a thousand times better. I ran a wire and grounded the alternator to the voltage regulator, and then to the battery- I grounded the taillights, etc, etc, etc.

Everything has been working excellent, bright lights, blinkers actually blinking without taking a minute between each blink, and so on.

Yesterday I left work really late and turned on the lights-

All of my lights now start to dim, then get bright, and this cycle continues at a constant rate. Engine rpms have no effect.

Anyone know what the h-e-double hockey sticks is going on?

It gave me a banging headache watching it the whole way home.
 
It's probably the old points type voltage regulator ticking on and off. You can get a modern electronic version that keeps the voltage more constant (I don't have the part number).
 
I ditched the old points type voltage regulator when I did everything else. I got a NAPA one that is much better.
 
I had that problem and had to replace alternator brushes. That took care of it.
 
Just about has to be alt or reg. Gauge voltage limiters can cause strange conditions but rarely effect the entire system for more than a minute before it frys.
 
And of course, both the alt and reg are new.
The reg cost me $50+ as I got the better one that Dan suggested, the alt was a reman- could that be the issue?

How do I replace the brushes?

I kept the old alt, which is a reman as well and was hurting, at least by the looks of it. Maybe I'll switch them and see what happens.

I also have a new replacement reg that I can swap and see if that works.
 
i'm always wary of reman alternators. i've had terrible luck with the ones from big box auto parts store.. napa, checkers, etc.
now i always go straight to my local auto electric shop, they always have parts that seem to work better the first time.
 
I'm just wondering why you grounded the alternator to the voltage regulator?
Alternators are usually grounded to the block and voltage regulators through the body and sometimes a wire is run from 1 of the mounting bolts to the block also. I don't know if connecting the regulator body to the alternator housing would have any effect.
I would check to make sure that the regulator has an effective ground and that the diodes on the alternator are functioning properly, but it sure sounds like a ground problem.
 
Have you tried putting a multimeter at various points in the system to trace back to the source of the fluctuation?
 
I have to ask because I think I have an overload in my head. I have a similar problem. I have a ground from my alternator to the body, I have a ground from the battery (neg) to the eng block and I put a new ground strap from the battery (neg) to the body. I added another ground from my valve covers to the body.

My lights go dim and bright when the car comes to an idle. Also my inside gauges do the same.

I was told to add the extra grounds from the battery to the frame and from the valve cover (passenger side) to the body, so I did, still the same. I have a powermaster alternator and a red top battery.

I also have to use my high beams when driving cause my lights seem so dim.

One other problem that I seem to always have is with my Tach. I have checked my connections which all seem fine however it will work just fine for a few days and then like the other night it will just stop and then start again. At idle it the needle will go all the way down, however upon acceleration it will go back up again. Sometimes bouncing around, up and down and then again at idel, just stop. This is driving me nuts.

Whew,,,,,,,,,,that was a mouthful. lol Suggestions????
 
Local auto electric shop, I'll have to find one.
I never had an original alternator to rebuild, just an old reman, so I had to get a new reman. One crappy alt to another.

My low beams blew out on me, and with a little help from FABO:
http://www.forabodiesonly.com/mopar/showthread.php?t=97571
That's where I got the notion to ground everything together.

I have not tried putting a multimeter at various points in the system to trace back to the source of the fluctuation because I don't have one, and I do not have any experience tracing electrical problems using one.

I'll try to find an electrical shop so I can get a good alt and cross my fingers.
 
"I have not tried putting a multimeter at various points in the system to trace back to the source of the fluctuation because I don't have one, and I do not have any experience tracing electrical problems using one."

That's like saying, "I cannot fix my motor because I don't have any wrenches or sockets".
 
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