Battery light constantly on (and low voltage on gauge)

[gavin]

I have a similar problem. I have installed new battery and alternator. The volt meter is low and warning light is on. What next.

wiring.

it's possible a ground wire is either #1 not making good contact, or #2 is corroded.

I would check the ground wire from the battery to the frame/engine block.

also, try reading voltage at the battery. With and without the truck running.

 

[Steeda90GT]

I agree. I cleaned up some of wiring just in case.

 

[kgbrgv]

I will start checking on the ground cables and wires. Probably will replace terminal ends on both ground and positive cables. Both are factory ends. I did notice when I installed the new battery and connected the leads they were not making good contact. I removed and scraped inside of both terminals. The made enough contact to start and run but the charging light has been itermittently between starts coming on.

 

[gavin]

I will start checking on the ground cables and wires. Probably will replace terminal ends on both ground and positive cables. Both are factory ends. I did notice when I installed the new battery and connected the leads they were not making good contact. I removed and scraped inside of both terminals. The made enough contact to start and run but the charging light has been itermittently between starts coming on.

my dad had a problem last summer with his Dodge not starting.
It seemed after putting the battery charger on the battery, or jumping it, would work.

turned out to be a bad positive cable to the battery. The cable looked perfect, but it was apparently corroded inside.
Once the cable was replaced, he's had no issues getting the truck started anymore.

It is possible that you are having a similar issue.

 

[kgbrgv]

I installed new cable ends on post positive and negative.

At first that seemed to solve the problem. About 2 hours later I checked again and had same issue again. Next I will try new cables!!!!!!!!!!!!! This is very frustrating. It has good enough connection to start with no problem. But there is not enough connection to send the correct amount of power to the alternator??? I will not give up. Cannot afford to have truck in shop. I have to same my dollars for Wall Street and Washington!!!!!!!!!!!!!!!!!!!!!!!

 

[gavin]

have you actually checked the voltage at the battery terminals with a multimeter, with and without the truck running?

 

[alohamonte]

at what mileage are you 2nd gen guys replacing your ALT? Just curious since mine is original.

 

[Steeda90GT]

Mine went out at 114,000 miles.

 

[Blee1099]

Check the resistance on the cables from end to end. Should be less than a few Ohms anything more I would replace them.

 

[gavin]

I replaced mine at... umm.. 150k miles or so? but I don't think it ever actually had any issues. I believe it was the belt slipping. It was also putting out ~15v or just shy of it.

I installed a 200 amp alt, which turned out to be total crap and caused a lot of problems. Went back to the OEM (thank God I didn't get rid of it!)

 

[Dc monster 91]

Ok I am havin the same problem with my aerostar, it'll start up fine and eerythin voltage goe up as normal and drops with the lights on(very little) but after about ten minutes the battery light comes on I checked the battery it's good and the alternator was teste and passed, my final decision is to get a new voltage regultor, oh and another thing is it'll do this randomly one days it'll work fine no light oter days it'll come on and off

 

[Comacoz]

there's a 15amp fuse in the fuse box under the hood thats for the battery, it tells the alternator to charge it. check to make sure it's not blown.

 

[koda2000]

there's a 15amp fuse in the fuse box under the hood thats for the battery, it tells the alternator to charge it. check to make sure it's not blown.

dude... you're posting to a thread that's over 2 years old.

 

[Comacoz]

dude... you're posting to a thread that's over 2 years old.

doesnt mean somebody's not currently looking at this thread and could use any helpful information now.

 

[pbnj22]

doesnt mean somebody's not currently looking at this thread and could use any helpful information now.

i hope you didnt spend the last 6 months trying to come up with that..

 

[Crowbar317]

Aftermarket alternators

this can happen when you purchase aftermarket alternators. There is a design flaw in the alternator. The problem is that when you truck is idling, and the serpentine belt is running much slower, it's not spinning fast enough to charge your battery during idle.

If you buy an aftermarket Alternator, it is imperative you check the pulley diameter. If it is larger it will spin slower so you must change pulleys to get the proper rpm at the alternator especially at idle. This was a problem with Pontiac in the 70's especially when equipped with high torque starters. I always check that when changing Alternators.
I have the battery light problem too but I know it's not the alternator, battery, diode, or any relay. Possibly the ignition switch (which is connected to the key cylinder by a shaft (so wiggling the key may not do the trick) or the terminals. My problem started with the battery light flickering then remaining on. I drove home a half hour but the truck was dying so I ducked into a Deli and had someone charge me up with jumper cables. Ten minutes later and it was charging again. When I got home and restarted the truck the light was back on. Check the battery and it had 12.5 volts I can start the vehicle and the battery light is on. Drive down the road and sometimes it goes off. It is charging! I stop the truck then start it back up and the light is on again. It is not charging! There is no generation to the battery and the light gets brighter as the engine rpm goes up. I changed batteries because it was only the second battery in that truck - (the original lasted until 2006).
After changing the alternator and having proper voltage from it - I still have the same problem. Existing problems do carry over to new installed parts. I don't feel too bad about buying the alternator as I was contemplating on changing it anyway since it was 18 years old as I don't like to be stranded. So I will most likely change the battery terminals and recheck the wiring and load test the new battery. (Squirrels, mice, and chipmunks do terrible things to wiring).

 

[Crowbar317]

old posts

Seems this problem is a lasting one. I came on this site because I am experiencing this problem as well. I have found a lot of nonsense and some good ideas. Some people think that just because the post is old the problem isn't relevant anymore. How wrong! Some people, like myself, maintain their vehicle well so problems take longer to present themselves. So if I can peruse an older post and find a solution to my problem and offer some of my experiences as well all the better. After all the purpose is to resolve problems isn't it?
If the posts are not relevant anymore then they should be disabled so they can't be viewed, just sayin~