Could this be early sign of battery at end of life? (1 Viewer)

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2001LC

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My 01 LC shows normal charging on the dash indicate. But I've noticed when headlights are on, the indicator light of the fresh/recirculating air button dims (cabin blower fan off). I've noticed a few other electrical gremlins lately as well.

What do you think, is battery at end of life or?
 
Check alternator before replacing battery. Most auto parts stores will do it for nothing. Doesn't sound like a problem with the battery.
 
^ agree. Check the alternator first.
 
Not to be ornery, but I'd suspect the battery or connections first. An alternator struggling to deal with a failing battery could produce the symptoms and batteries fail more often than alternators. Especially if the dash gauge shows normal charging. If the battery is more than 4-5 years old, I would just go ahead and replace it and then worry about the alternator if that doesn't fix it.
 
^ What?
 
My 01 LC shows normal charging on the dash indicate. But I've noticed when headlights are on, the indicator light of the fresh/recirculating air button dims (cabin blower fan off). I've noticed a few other electrical gremlins lately as well.

What do you think, is battery at end of life or?


I believe what you are describing is "working as designed". On both my 06 LX and on my son's 00 LC, the fresh/recirculate indicator dims when the headlights are turned on.
 
I believe what you are describing is "working as designed". On both my 06 LX and on my son's 00 LC, the fresh/recirculate indicator dims when the headlights are turned on.

Same here mine have always done that, I think it's to prevent them from distracting you at night.
 
If you have AAA premier (top of the line black card) you can have them test the battery and if it tests bad you can get a free one or take the slip they give you and submit a claim up to $125. You get one claim per household per year.
 
@jLB & @landylover21 may very well be correct. It's very possible I just never noticed this dimming, as I've keep light switch in auto position for 13 years. Has anyone else notice this dimming when lights turned on in a no NAV rig?

I've become more aware of all systems on my LC lately, as I've been comparing to my LX. The LX is new to me as many of you know, and had Mickey & Minnie living under the intake dinning on a knock sensor wire.

Notes: I now tend to turn lights on & off manually, after reading auto setting has a parasitic draw when parked.
It's a Wal-Mart battery that has been in service just under 5 years, surprisingly.
 
The best way to test alternator/battery at home is to put a voltmeter across the battery when running and read voltage, it should read between 13.5-14.5v then put as much load on as possible. Then leave the leads on the battery and disable the vehicle from starting i.e remove fuel pump fuse, then crank the engine for 15 secs and read the voltage, it shouldn't drop below 9.5 volts. Then do a voltage drop test on main battery leads when cranking engine(max load) max drop is 0.5v but with such big short leads it should be more like 0.1v.

Ps. Resting voltage should be 12.6v plus for 100% charged battery
 
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Thanks Julian, I'll try that.

Still hoping to hear if others find this dimming to be a normal condition?
 
Just checked mine, all buttons if activated dim when headlights are on. It is to stop glare when it is dark as you don't need as much light output to be noticeable.
 
Mine does the same thing. It's been like that for years. Maybe it the elevation? Joking...
 
Just to follow up on old thread.

Although it seems auto dimming of some dash lights are normal when headlights turned on, the battery did need replacing. The battery was just getting old and weak, so not changing as well it once did. This weakened condition appeared to further dim the dash lights more than I would normally see. I also noted some blue at the body ground wire. This would indicate it may be time for the big three wiring upgrade also.
The King Ground wire.JPG
 
That it's probably time for the "Big Three Upgrade"

A&P went on to say; "good idea to check resistance of cable (off the vehicle), comparing to new cable. That if I see corrosion near lead, you can bet it's into/around wire strands and lead. This will increase resistance and must be replaced."

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Here's the full store:

This seem like a good thread to share something I just learned from a United Airline mechanic.

While on a flight to LA from Denver to buy The Black Knight (yes I name them) last week with my girlfriend, we got stuck in the very last row. She took window seat, while I the aisle thinking/hoping no one would take the center. Well, a guy 6'4" did, that couldn't get his knee to fit in, so I gave him my Knee space. We got to talking gear-head stuff the whole flight. He into diesel Mercedes and me into 100 series (what else). I gave you the above story, so you know where info comes from!

He told me in aircraft they have a tool that used to clean/grind under the ground/negative connection(s) on the air frame. They then add a dab of sealant to spot before bolting back on the the ground lead. They finish by cover assemble (Air frame, ground lead & bolt) with the sealant.

He said he's does same procedure on his car's. Cleans paint off from under leads on grounds and then seals. He's helped friends do the same, which cleared up electrical issues they had. He said the paint between lead & body metal increases resistance.

I asked "what is this sealant", he gave me a the name of this special aircraft sealant, but said I did not need it, that I could just use silicone sealant. That as bolt tightens, sealant squeeze out making a good contact and a perfect seal around the lead end.

He went on to say; good idea to check resistance of cable (off the vehicle), comparing to new cable. That if I see corrosion near lead, you can bet it's into/around wire strands and lead. This will increase resistance and must be replaced.
 
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Could grease work in place of silicone sealant? I have used chassis grease and marine grease around all exposed terminals in the past with good luck. Sealing oxygen battery fumes and other elements out of connections I believe is key. Whenever I rewire I use shrink tube around the exposed wires as in your link and gett all grounds to bare metal. I wish all factory connections came with shrink tube.
 
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