Battery light coming on

[WhiteLX]

This is a problem I have had for probably the last year. i can't seem to figure out what is causing it. The truck is an 89 with the 2.9L V6.

The battery light on the gauge cluster is coming on. Sometimes it's constantly on, sometimes after driving for a long time it goes out, but most of the time it's flickering. I took the truck to autozone to have them test the charging and electrical system. Their Autometer brand tester said the battery was bad. Odd, the truck never has a problem starting and prior to the test the light had been coming on for several months.

I dismissed their diagnosis and continued to drive the truck. Several months passed and one day the truck didn't start after a short drive to pick up some food. I took at look at the cables, wiggled them a little, and it fired back up.

I decided I should probably replace the battery. It was an old Optima redtop that had been in my Mustang for a few years and then in my ranger for a few more years. I replaced the battery, cleaned the terminals, and nothing changed. I added some additional engine to chassis grounds, nothing changed.

The only things I haven't done are replace the battery to engine cable and test the alternator off the truck.

 

[Spott]

The wire running from the warning lamp to the alternator, might be grounding out somewhere. That would cause the lamp to light intermittently. Follow the wire and see if it has any bare spots.

Another possibility: test the resistance on the positive battery cable, while wiggling it (unhook it from the battery first). You might have a loose or intermittent connection.

Spott

 

[1996DANGERRANGER]

mine does it too. . but mine does it becasue the clip for the sesor wire on the alternator itself is broken so it wiggles loose. if i pullit off it comes on all the time. if i put it on tight it nevers comes on

 

[WhiteLX]

It's been a few years, but I finally found the problem, or at least I think I have. I won't know till I get it back together. One of the spade terminals on the alternator rectifier broke off in the connector. I noticed it when I pulled the alternator to get more room to change the spark plugs and tighten the valve cover bolts. It must have been making an intermittent connection which caused the light to flicker.

Perfect time to upgrade to a 3G alternator as I have been wanting to install an electric fan.

 

[kimcrwbr1]

This made me smile just for future reference there is a reason it is called a idiot light. When the light comes on you should find out why as quick as possible. You flat got lucky it didnt leave you stranded somewhere. First thing you need to do after you get it back together is do the load/ noload test on the charging system. If you want to keep an eye on the system just put a volt meter that tells you battery voltage with the ignition on. If the idiot light comes on do not just keep driving it find out why!

 

[kimcrwbr1]

http://www.therangerstation.com/tech_library/chargingsystem.shtml
Use the tech library alot of good info you can use there. Read this article all the way through a couple times and then do the load/noload tests to confirm your repair.

 

[WhiteLX]

This made me smile just for future reference there is a reason it is called a idiot light. When the light comes on you should find out why as quick as possible. You flat got lucky it didnt leave you stranded somewhere. First thing you need to do after you get it back together is do the load/ noload test on the charging system. If you want to keep an eye on the system just put a volt meter that tells you battery voltage with the ignition on. If the idiot light comes on do not just keep driving it find out why!

excuse me?

Maybe it wasn't clear, but a load/no load test had been performed. It passed. The truck has a voltage meter, if there was a problem with the alternator failing and the truck running off battery voltage, I would have known.

It's called an idiot light because they don't provide any information when illuminated. I attempted to find out why when it initially came on, there was nothing that stood out and the truck continued to operate as normal for more than 3 years.

Maybe you should consider reading through your post and the thread a couple times to confirm your thoughts before hitting submit.

 

[kimcrwbr1]

Maybe in another thread you mentioned the volt meter and load/noload test I was just going by the black parts of your post. I still havent learned how to read the white parts.

 

[RonD]

excuse me?

Maybe it wasn't clear, but a load/no load test had been performed. It passed. The truck has a voltage meter, if there was a problem with the alternator failing and the truck running off battery voltage, I would have known.

It's called an idiot light because they don't provide any information when illuminated. I attempted to find out why when it initially came on, there was nothing that stood out and the truck continued to operate as normal for more than 3 years.

Maybe you should consider reading through your post and the thread a couple times to confirm your thoughts before hitting submit.

You are correct WhiteLX.
And thanks for the heads up about checking connectors and pins closer

kimcrwbr1's post was out of line and even worse, no help in this case, which is odd he usually has good info

 

[kimcrwbr1]

This is a problem I have had for probably the last year. i can't seem to figure out what is causing it. The truck is an 89 with the 2.9L V6.

The battery light on the gauge cluster is coming on. Sometimes it's constantly on, sometimes after driving for a long time it goes out, but most of the time it's flickering. I took the truck to autozone to have them test the charging and electrical system. Their Autometer brand tester said the battery was bad. Odd, the truck never has a problem starting and prior to the test the light had been coming on for several months.

I dismissed their diagnosis and continued to drive the truck. Several months passed and one day the truck didn't start after a short drive to pick up some food. I took at look at the cables, wiggled them a little, and it fired back up.

I decided I should probably replace the battery. It was an old Optima redtop that had been in my Mustang for a few years and then in my ranger for a few more years. I replaced the battery, cleaned the terminals, and nothing changed. I added some additional engine to chassis grounds, nothing changed.

The only things I haven't done are replace the battery to engine cable and test the alternator off the truck.

This is BS the first time the noload/load test was mentioned in this thread or the volt meter was when I did to help him. I care alot more about motors than your sensativity. I am sorry I hurt your feelings.

 

[WhiteLX]

This is BS the first time the noload/load test was mentioned in this thread or the volt meter was when I did to help him. I care alot more about motors than your sensativity. I am sorry I hurt your feelings.

Again with the reading comprehension and attitude. You even quoted it, but you can't seem to understand it. I'm not even going to bother pointing out the load/no load test, because you'll find some way to discredit it.

I didn't have to follow up to this post. I could have just let it die and be of no help to the next person. But as a benefit to the community, I responded with my findings.

 

[RonD]

................

I didn't have to follow up to this post. I could have just let it die and be of no help to the next person. But as a benefit to the community, I responded with my findings.

And we appreciate it