Electrical issue... dimming interior lights while driving at low RPM

[deevergote]

I know this probably sounds like a noob issue... and yeah, it probably is

Anyway, under 2800 RPM, my interior lights get really dim. They used to dim a little before, but it's really noticable now. When I rev the engine, they get brighter. Loud volume and heavy bass (no system) from my head unit caused it to dim on the bassy parts. At times, my speedometer needle would dip down as I decelerated.

Obviously, all my issues involve the engine speed. I have an Unorthodox Racing crank pulley, which is smaller than the stock piece (so it spins the alternator pulley slower). That MIGHT be an issue. Now, I'm wondering how much of an issue that actually is... I mean, am I killing my alternator? I'm afraid I might have done some serious damage if the pulley is bad for it. Is the underdriven alternator just not charging the battery properly? As in, my one year old battery is going, but my underdriven alternator is still OK?

Anyone who is knowledgable about these things, please help! Electrical issues are NOT my forte! I don't want to replace things I don't need to replace... However, I don't know how to properly check any of that either!

[TysCb7]

It could be the belt tension.

[deevergote]

I have no system... I don't think my Pioneer head unit and Pioneer 2 way 6.5" speakers are killing it How do I check to see what it's putting out? Multimeter? Like I said, electrical stuff is beyond me. It's something I never bothered to learn... I guess it's time!

However, the belt tension IS off a bit... it squeals like crazy on startup. I've tried tightening it a few times, and it never seems to fix it. On my JDM H22, using the alternator that came with the swap, all I need to do is loosen the bolt behind the unit (the deep one) and then twist the adjustment screw on the bottom front, right? Which screw is that? I think I've been turning the left one... It's so tight down there with my power steering, cruise control, and AC (all three I really don't want anymore... but I have yet to remove...)

Also, I adjusted my idle... it was around 700-800, and I put it back up to about 1000. That seemd to fix things a little.

[F22-GURU]

Bloody Noob Question I don't know !!

Seriously though The Underdrive Pulley diameter itself wouldn't make a difference to the Alternator Charge Rate above 1200 RPM.

This is an excerpt from my Alternator & Batteries Write Up...

An automotive alternator is a THREE PHASE GENERATOR with a built-in RECTIFIER CIRCUIT consisting of SIX DIODES.
As the pulley is rotated by a belt connected to the car engine's crankshaft, a MAGNET is spun past a stationary set of Three-Phase Windings called the STATOR, usually connected in a Y configuration. The spinning MAGNET is actually an ELECTROMAGNET, not a PERMANENT magnet. Alternators are designed this way so that the MAGNETIC FIELD STRENGTH can be controlled, in order that OUTPUT VOLTAGE may be controlled independently of rotor speed. This ROTOR MAGNET coil called the FIELD COIL, is ENERGIZED BY BATTERY POWER, so that it takes a small amount of electrical power input to the alternator to get it to generate a lot of output power.

ELECTRICAL POWER is conducted to the rotating field coil through a pair of copper "slip rings" mounted concentrically on the shaft, contacted by stationary carbon "brushes." The brushes are held in firm contact with the slip rings by spring pressure.

Many modern alternators are equipped with built-in VOLTAGE REGULATOR circuits that automatically switch battery power on and off to the rotor coil to regulate output voltage.

The belt tension would be a big issue, because if the belt is slipping then the Alternator Pulley may not be spinning fast enough at low rpm to replenish the Battery Power which is being used. The Underdrive Pulley spinning the Alternator Pulley Slower would only become an issue at Normal Idle. Which would be exacerbated by a loose belt. Worn or Sticking Volt Reg Brushes or Slip Rings wouldn't help either.
I advise to get a 'New' Alternator Belt & Tension It to Specs. If the old belt has been slipping then it can overheat due to friction and damage the belt surface, which will cause lateral cracking of the Polyribs later on. Lubricating a slipping belt will only prolong the agony.
I would also look at Amping Up the Alternator to compensate.
Funny thing is the amount of young blokes that get their humongous Doof Doof's installed with the massive Wiring and fuses but keep running the original alternator.

-Geoff-

[h22sparkle]

No deev tighten up the belt a little bit more. If the belt isnt on tight enough it will start messin with shit that the altenator usually charges up to make constant power . This has happened to me befoe aswell just to let you know

[turboaccordlx]

start car. . . disconnect battery pos post while running. If it dies its the alt.

[xaxis360]

If you installed a smaller pulley, the alternator will spin faster. That should help your situation. However, there is a limit on how fast our alternators can spin. I believe it is 7200 which wouldn't normally be an issue. However, with a smaller pulley, you could reach that at a much lower RPM causing damage to the internal compnents of it. Just an idea...

[deevergote]

Well... considering I wind my motor out to 7400 on occasion... probably more than I should... Maybe that can do some damage. Of course, the alternator should be the one that came on the motor... I don't think Honda would put an alternator on a motor capable of 7500+ RPM if it couldn't handle it... still, who knows!

Geoff... see what I mean about nobody reading stickies and the like! I did search a bit and found nothing that made sense. This is one of those situations where I'm not absolutely sure of what the cause is, so I don't know what the symptoms are pointing towards. I know of a shop that rebuilds alternators... I might check with them to see how much it'll cost to either have them do it, or sell me the parts so I can fumble my way through!
Also, what do you mean about amping up the alternator? (remeber, I rode the short bus to electrical school...)

I also thought it might be a grounding issue.

[TysCb7]

When my alternator finally gave out I just bought a used OEM off of ebay for 30 bucks it had about 60k on it and its lasted me forever. I wouldnt rebuild the one you have now theres really no point, OEM all the way.

[deevergote]

With the H22 alternator (according to Chilton's, it's different than the F22 one) which is the adjustment screw? I'll feel like a dumbass if I've been turning the wrong one! Also, is it the standard lefty loosy, righty tighty?

[TysCb7]

Yep just make sure you losen the bolt that lets the alternator pivot, so it can adjust the alternator.

[deevergote]

Which screw underneath adjusts it? There are two... and with my power steering, cruise control, and air conditioning, I can't see which one is the one to turn to adjust it! Man, I gotta pull that crap...

[Ilikebigbutts]

take it to a shop and do a charging system output test or have auto zone test your altenator(i wouldnt trust them though).

ILBB

[TysCb7]

What I didnt show was the actual bolt you have to tighten in order to get better belt tension which is the only bolt not pictured, its right next to the bolt that says leave tight, just slowly tighted it but be sure you loosen the bolts labeled before you tighted it otherwise it will not get any tension.

[deevergote]

Awesome. Thanks! I think I may have been turning the wrong one... I hope I haven't been doing any damage! So it's the one on the right I need to tighten... Normal right-turning will do it? For some reason, I thought I heard something about turning it the other way...