ABS light and Battery light mysteries

[Canadian TLC]

Hey folks,
Here’s a couple mysteries for ya!

My ABS light comes on whenever I turn on my headlights switch. (I don’t have Auto headlamps)

And my battery light comes on when it’s damp or raining out.

Anybody have any insight on either of these issues?

Thanks
Joe

 

[Trunk Monkey]

Model and year of truck in your sig would help. My first stab without more info would be water intrusion causing issues.

 

[Canadian TLC]

Model and year of truck in your sig would help. My first stab without more info would be water intrusion causing issues.

I was leaning in that direction as well. I know I do have water coming in and I NEED to get that resolved. That was a big issue in my 100.
2006 HZJ105

 

[bubfuji]

Sounds like your alternator is going bad. The additional load from turning on your lights is straining the alternator. Or you battery is too old causing the alternator to stain. A weak battery can damage an older alternator. Battery connections in good shape? Do you have corrosion growing on the positive or negative terminal. + side corrosion only, says the alternator is overcharging (weak battery, or going bad alternator). a (-) negative only corrosion points to bad ground connections. Corrosion on both terminals points to an end of life battery. With the engine off, what is the battery voltage? with the engine running what is the voltage, then turn the lights on and read the voltage. The engine off to running voltage should be about a 2-5 volt difference. What is the overnight voltage drop. Measure after running, with the engine off. Then check again the next day or a few hours later. anything more than 2-5 volts points to the battery not holding a charge. However, most likely your alternator is on the way out. If the alternator is bad, and the battery(s) is more than 3 years old. install a new battery as well.

 

[Canadian TLC]

Sounds like your alternator is going bad. The additional load from turning on your lights is straining the alternator. Or you battery is too old causing the alternator to stain. A weak battery can damage an older alternator. Battery connections in good shape? Do you have corrosion growing on the positive or negative terminal. + side corrosion only, says the alternator is overcharging (weak battery, or going bad alternator). a (-) negative only corrosion points to bad ground connections. Corrosion on both terminals points to an end of life battery. With the engine off, what is the battery voltage? with the engine running what is the voltage, then turn the lights on and read the voltage. The engine off to running voltage should be about a 2-5 volt difference. What is the overnight voltage drop. Measure after running, with the engine off. Then check again the next day or a few hours later. anything more than 2-5 volts points to the battery not holding a charge. However, most likely your alternator is on the way out. If the alternator is bad, and the battery(s) is more than 3 years old. install a new battery as well.

Yes indeed. Since I last posted the alternator has gone from spotty to near failure. It does still put out 12+ volts sometimes then it drops right off. Not sure if it’s brushes or regular or what but it gets super hot almost smoking.
I just ordered a replacement… just hope this one holds on til it arrives.

 

[bubfuji]

Good News.

 

[Canadian TLC]

Good News.

I just bought the truck so I have no way of knowing how old the batteries are or if this is the original alternator. I’ll get the batteries load tested once it’s charging properly again and go from there.
Thank you for your support.

 

[bubfuji]

See if there is a date stamp on the batteries.