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  #1  
Old 03-23-2011, 05:47 PM
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K_Dub K_Dub is offline
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Confirm my problem is Alternator related

Hey folks. This problem just reared its head for the first time today. When the revs drop below 1500rpm some of my dash lights slowly illuminate. Once I get back above about 1.7K they fade out.

I've read many a thread about "Christmas Lights" without any real description of what that means. In my case only the "steering, battery, stop lamp, brake and ABS" lights illuminate. I suspect my alternator is on its way out, but I always check here before I go spending my hard earned dough. If indeed it's as I suspect I'll finally have run out of excuses for not picking up a Maniac and doing the infamous wiring upgrade.

Thanks for humoring my mechanical insecurity. Despite doing quite a bit of work on this car, I'm still a noob at each task I undertake.
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'92 LS-L "Bandit" #362 formerly dark teal, repainted by prev owner
Mods: ECUTune 2v7f, Earthworm bushings, Pioneer DVD/Bluetooth phone, Infinity Reference all around, tint, 17" wheels, custom seat belt computer, velcro visor

Buying parts is like car payments. Someday she'll be all mine.
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  #2  
Old 03-23-2011, 05:56 PM
Blacky Blacky is offline
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Re: Confirm my problem is Alternator related

You can check the output voltage easily if you have a multimeter. Positive to the connection under the round rubber cover on the top of the alternator and negative to the neg battery post. Should read around 14.5 volts. Most auto parts stores will do a free alternator test also.
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  #3  
Old 03-23-2011, 06:40 PM
oab_au oab_au is offline
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Re: Confirm my problem is Alternator related

Quote:
Originally Posted by K_Dub View Post
Hey folks. This problem just reared its head for the first time today. When the revs drop below 1500rpm some of my dash lights slowly illuminate. Once I get back above about 1.7K they fade out.

I've read many a thread about "Christmas Lights" without any real description of what that means. In my case only the "steering, battery, stop lamp, brake and ABS" lights illuminate. I suspect my alternator is on its way out, but I always check here before I go spending my hard earned dough. If indeed it's as I suspect I'll finally have run out of excuses for not picking up a Maniac and doing the infamous wiring upgrade.

Thanks for humoring my mechanical insecurity. Despite doing quite a bit of work on this car, I'm still a noob at each task I undertake.
The 'Christmas tree lights' is just the way Subaru tied all those lights into the Alternator light. So any Alt problem lights all the vital units, lights also. They probably thought that if the Alt stopped charging and the driver did not take any notice of the Alt light, the power steering, ABS, booster, may stop working, and the car would be unsafe. So they made all the lights come on to frighten the $hit out of the driver to get it fixed.

The Alt will bring on these lights for a few different reasons. No charge, low charge, too high a voltage. In your case as the lights come on at low speeds, it is probably low charge. Just have it checked out.

Harvey.
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  #4  
Old 03-23-2011, 11:57 PM
Cam Cam is offline
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Re: Confirm my problem is Alternator related

Start your car and pull a battery cable. Either one. If the car dies, then the alternator will be the problem 99.9 percent of the time. Checking with a multimeter is a good idea, in case the voltage regulator is failing. If the output is over 16 volts, replace the alternator. However, this would be likely if the symptoms occurred as the rpms raised, not "dropped below 1500". I would just pull a battery cable...
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  #5  
Old 03-24-2011, 12:19 AM
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K_Dub K_Dub is offline
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Re: Confirm my problem is Alternator related

Quote:
Originally Posted by Cam View Post
Start your car and pull a battery cable. Either one. If the car dies, then the alternator will be the problem 99.9 percent of the time. Checking with a multimeter is a good idea, in case the voltage regulator is failing. If the output is over 16 volts, replace the alternator. However, this would be likely if the symptoms occurred as the rpms raised, not "dropped below 1500". I would just pull a battery cable...
I'm thinking this is a sure thing. It got me home (Subarus always do) but as I made the turn into the driveway the headlights (HID) flickered and went out. I'll order up the parts tomorrow, but I think the car's stationary 'till they arrive. Thanks, everybody, for the advise. I'll take the multimeter to it tomorrow and get the final confirmation.
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'92 LS-L "Bandit" #362 formerly dark teal, repainted by prev owner
Mods: ECUTune 2v7f, Earthworm bushings, Pioneer DVD/Bluetooth phone, Infinity Reference all around, tint, 17" wheels, custom seat belt computer, velcro visor

Buying parts is like car payments. Someday she'll be all mine.
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  #6  
Old 03-24-2011, 06:04 AM
dcarrb dcarrb is offline
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Re: Confirm my problem is Alternator related

I've gotten the "Christmas lights" once in each of my cars, promptly checked the drive belt tension/integrity, replaced the alternators with locally available remans, then went about my driving.

dcb
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  #7  
Old 03-24-2011, 10:36 AM
torxxx torxxx is offline
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Re: Confirm my problem is Alternator related

that light issue is usually 90% Alternator failure or connection failure @ or two the alternator. Check belt tension also. If alternator isnt putting out 13.5+ volts at idle, its got a dead diode (I think thats the part) either way its not charging fully, and Fuel injection draws a buttload of power to operate
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  #8  
Old 03-24-2011, 04:38 PM
oab_au oab_au is offline
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Re: Confirm my problem is Alternator related

Quote:
Originally Posted by Cam View Post
Start your car and pull a battery cable. Either one. If the car dies, then the alternator will be the problem 99.9 percent of the time. Checking with a multimeter is a good idea, in case the voltage regulator is failing. If the output is over 16 volts, replace the alternator. However, this would be likely if the symptoms occurred as the rpms raised, not "dropped below 1500". I would just pull a battery cable...
Wow don"t do this.

Disconnecting the battery while the Alt is charging can cause a high voltage spike to go through the system, that can destroy units just like when the regulator goes out. Use a multimeter.

Harvey.
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Tell it like it is!

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97 Liberty GX Auto sedan. 320,000Kls.
04 Liberty 30R Auto Premium. 92.000kls.
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  #9  
Old 03-24-2011, 04:54 PM
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K_Dub K_Dub is offline
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Re: Confirm my problem is Alternator related

Quote:
Originally Posted by oab_au View Post
Wow don"t do this.

Disconnecting the battery while the Alt is charging can cause a high voltage spike to go through the system, that can destroy units just like when the regulator goes out. Use a multimeter.

Harvey.
Yeah, I've heard bad things about that trick on newer cars. It's a moot point anyhow because I drained my Optima Red driving home last night. I've got 0.5v across the battery and no start. Bummer.

I've ordered up my HO Alternator from Maniac. Why can't this stuff ever happen on a Monday so I can get parts by the weekend? Thanks SVXCESS for the shipping promo. Still works!

I suppose I'll trickle charge my battery before the new part shows up. I've also got to look into acquiring the parts for the wiring upgrade. The belt just started to periodically squeak at startup, so I'm thinking I might do that as well.

Between my periodic stalls/no starts that I've posted about and the dash lights dimming when my blinker is on, I'm looking forward to getting my current sorted out. As always, thanks to this forum for keeping me on the road, and preventing me from frying my whole car.
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'92 LS-L "Bandit" #362 formerly dark teal, repainted by prev owner
Mods: ECUTune 2v7f, Earthworm bushings, Pioneer DVD/Bluetooth phone, Infinity Reference all around, tint, 17" wheels, custom seat belt computer, velcro visor

Buying parts is like car payments. Someday she'll be all mine.
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  #10  
Old 03-27-2011, 06:12 PM
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K_Dub K_Dub is offline
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Re: Confirm my problem is Alternator related

Update #1.

I took my Optima Red Top into Kragen for a recharge, and they said it was dead and unchargable.

They then asked for my phone number, looked up the transaction, and handed me my free replacement battery with no questions asked.

There were two guys in line with dead AC Delco batteries. No replacements for them.

I love Optima and my parts store today (Kragen/Checker/Shucks/O'Reilly Auto Parts). It's hard to find service like that these days.

They had the 175amp Mega-Fuse there for $5 but no fuse holder. I also didn't like the look of their 4 gauge wire, so the parts hunt continues.
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'92 LS-L "Bandit" #362 formerly dark teal, repainted by prev owner
Mods: ECUTune 2v7f, Earthworm bushings, Pioneer DVD/Bluetooth phone, Infinity Reference all around, tint, 17" wheels, custom seat belt computer, velcro visor

Buying parts is like car payments. Someday she'll be all mine.
Reply With Quote
  #11  
Old 03-27-2011, 07:13 PM
Cam Cam is offline
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Re: Confirm my problem is Alternator related

Quote:
Originally Posted by oab_au View Post
Wow don"t do this.

Disconnecting the battery while the Alt is charging can cause a high voltage spike to go through the system, that can destroy units just like when the regulator goes out. Use a multimeter.

Harvey.
I've done this hundreds of times. If it makes a spike, it is for such a short duration that it doesn't matter. I've never had any issues with this trick.
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'92 Ls-L Dark Teal
11:1 CR ECUTUNE pistons
ECUTUNE .256 duration intake/exhaust cams
ECUTUNE STAGE 2AV1 ECU
Z32 MAF/SR20DET injectors
Balanced & Blueprinted
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