Skip to content
View in the app

A better way to browse. Learn more.

Ultimate Subaru Message Board

A full-screen app on your home screen with push notifications, badges and more.

To install this app on iOS and iPadOS
  1. Tap the Share icon in Safari
  2. Scroll the menu and tap Add to Home Screen.
  3. Tap Add in the top-right corner.
To install this app on Android
  1. Tap the 3-dot menu (⋮) in the top-right corner of the browser.
  2. Tap Add to Home screen or Install app.
  3. Confirm by tapping Install.

Electrical intensity varies

Featured Replies

Hi all,

 

I have noticed that on my car, the electrical intensity varies depending on whether or not I am driving.

 

For example, at idle, my headlights, and interior lights will be a little dimmer than once I am driving. Nothing too bad, but still able to notice.

 

I have a 2.2 Legacy 1993 Non Turbo, stick shift.

 

BTW, I do have a brand spanking new battery, and am able to start at - 25 degree weather no problem.

 

Thanks in advance !

 

Cheers

 

JF

It happens when I apply the brakes........it's quite normal

Quite normal, has happened several cars that I've owned. If there was a problem it wouldn't likely be the battery anyways, it would be the alternator (e.g. if the dimming was severe). When the engine is running above idle the alternator produces more power, and is able to more than meet the needs of he accessories. when at idle, the alternator is more taxed, and less power is available for the accessories. That's it.

  • Author

Thanks,

 

It never happened to my previous cars, but I wasnt overly worried. I guess that my biggest fear was that the alternator or the voltage regulator was off...

 

In any case, thanks a lot !

 

JF

Since I've only noted it in older cars, perhaps it is a sign of a somewhat weakened alternator, but as long as it is a mild effect I don't think there's a problem. mine has been doing this since i bought it, and my battery charges fine.

 

 

 

Thanks,

 

It never happened to my previous cars, but I wasnt overly worried. I guess that my biggest fear was that the alternator or the voltage regulator was off...

 

In any case, thanks a lot !

 

JF

Hi all,

 

I have noticed that on my car, the electrical intensity varies depending on whether or not I am driving.

 

For example, at idle, my headlights, and interior lights will be a little dimmer than once I am driving. Nothing too bad, but still able to notice.

 

I have a 2.2 Legacy 1993 Non Turbo, stick shift.

 

BTW, I do have a brand spanking new battery, and am able to start at - 25 degree weather no problem.

 

Thanks in advance !

 

Cheers

 

JF

 

I suppose, if you bought the car used, someone COULD have put an 'underdrive' pulley on it. But, yeah, many cars I've had will do that at least a little.

I use the four way flashers a lot waiting for my wife in SF. It always affects the rest of the lights. Normal for one of these.

By the way we should establish a sell by date for these alternators. How long do they usually last?

Hi all,

 

I have noticed that on my car, the electrical intensity varies depending on whether or not I am driving.

 

For example, at idle, my headlights, and interior lights will be a little dimmer than once I am driving. Nothing too bad, but still able to notice.

 

I have a 2.2 Legacy 1993 Non Turbo, stick shift.

 

BTW, I do have a brand spanking new battery, and am able to start at - 25 degree weather no problem.

 

Thanks in advance !

 

Cheers

 

JF

 

Checklist:

 

Grounding - http://www.ultimatesubaru.org/forum/showthread.php?t=42606&page=1&pp=10

 

Do you hear an electrical hum coming from the area of your alternator? If so... Gone.

 

Lastly - Battery, Battery cables, and terminals. VERY Cheap and EASY to replace the battery cables.

 

Good luck, let us know what you find.

Dude, thanks much for this tidbit - I am making this my next weekend project!

 

 

 

Checklist:

 

Grounding - http://www.ultimatesubaru.org/forum/showthread.php?t=42606&page=1&pp=10

 

Do you hear an electrical hum coming from the area of your alternator? If so... Gone.

 

Lastly - Battery, Battery cables, and terminals. VERY Cheap and EASY to replace the battery cables.

 

Good luck, let us know what you find.

Do you guys clean and or replace your battery cable once a year or so? I clean the battery too when I'm doing this service. I like to clean both ends of the cables and the spot where the cable bolts on. Here in no salt country we have it a bit easier on corrosion, but I am sure bigger cables and a good ground will be helpful.

Mine is a brand-new battery, and I cleaned the cables well with a wire brush before attaching them. That darn new 1000 amp 875 CCA battery sure makes that new champion starter start the car with authority! But unfortunately does nothing for the lowered intensity. No matter, grounds will be cleaned soon and possibly even rewired. With red, just to tick everyone off ;)

 

 

 

Do you guys clean and or replace your battery cable once a year or so? I clean the battery too when I'm doing this service. I like to clean both ends of the cables and the spot where the cable bolts on. Here in no salt country we have it a bit easier on corrosion, but I am sure bigger cables and a good ground will be helpful.

Let us know the results! If I can run a few feet of gound cable and stop my reading light from flickering it would be worth it.

So I've been reading some of these threads regarding replacing of the battery and ground contact cleaning.....but I was wondering what brand of batteries everyone uses in their Subarus? The '03 Outback I bought a month ago looks like it still has the OEM, but we've always used the Sears line of batteries in our other cars when it came time to replace them.

I've been using Interstate since I could buy them at discount, but my guy retired so probably Autozone. A lot of them are made by the same makers with different stickers.

Please sign in to comment

You will be able to leave a comment after signing in

Sign In Now

Account

Navigation

Search

Search

Configure browser push notifications

Chrome (Android)
  1. Tap the lock icon next to the address bar.
  2. Tap Permissions → Notifications.
  3. Adjust your preference.
Chrome (Desktop)
  1. Click the padlock icon in the address bar.
  2. Select Site settings.
  3. Find Notifications and adjust your preference.