So here is the issue. I live in FL so it rarely gets too cold. But when it gets around 60 or lower I get a "Check Charging System" message on the screen. This will only popup if the engine is below 1800 RPMs for a minute or two. For example, I wake up and leave for work, it is 55 out and I start the truck up. I allow the truck to warme up just a minute or tow before I leave. The message will pop up. I start driving away, when I hit mid first gear the message is gone. I get to a stop light and the RPM drops and the message pops back up. I put it in neutral and give it some gas slowly, when I get around 1800 RPM the message goes away. I have checked major connections, it has a one year old battery and the alternator is 6 months old. It is a 2004 F150 Super Crew with the 5.4 V8. . . .any thoughts?

 

For some reason the alternator is not producing enough voltage. Did the correct pulley get put on the new one?

 

Yes, I made sure the pulleys were the same before installing the new one.

 

Could this be a bad battery? I have a voltmeter, how can I test this thing to find out what is going on?

 

If it is a re-man alternator have it tested. I have purchased bad / defective ones before. Advance auto and Autozone, around here anyway, will test them for free.

ck

 

I'm going to also guess its a bad alternator.....or loose wires???

 

sound's like a bad alternator to me to.How many miles are on your truck?I wouldn't think that the alternator would be bad already I just replaced the original alternator on my 94 f150 this past summer and it had 194,000 miles on it.

 

to check it with a volt meter do the following.
Turn the truck on and let it idle
touch your probes to the + and - leads on the cables
your meter should read about 14.XX
If it reads less you gotta bad altenator
While the truck is off, take your probes and test the battery, with the truck off and the probes on the terminal you should get a 12.XX reading for the battery.

 

Sounds like its a bad alternator, check to see if your lights are dimming or pulsing as the truck is running sometimes thats a symptom, make sure your connections are clean, battery,alt, etc.....and just to add to the thread, .... if you check your battery with a voltmeter you dont really get a true reading for what the battery is doing. It could read fine...ie 12v, but could have a bad cell, meaning it cant handle a load. A battery tester will test that by putting a 'load' on and telling you what the battery is truly capable of. I dont know if autozone or those places have those testers for use by customers, but a decent auto shop would.

 

Ok, So this morning it happened again. It was cold out and I was driving to a client about 100 miles away. About 75% there I get a message to check charging system, The RPM's were over 2000 but the weather was still cold out. When the message came on it went out after a minute or two. About 10 minutes later everything in my truck shut off except the engine. No radio, lights, windows, A/C, nothing. Even my gauge cluster went off like the truck was completely turned off. All the gauges were on '0'. I was in the middle of no where so I kept driving but making high rpms was a little difficult. I got off the highway and as soon as the rpms came down the truck died and I glided over to the side of the road. I tried to start the truck and I here clicking coming from the electric panel area, it was not the starter or the solenoid. Each time I did this the radio would come on and the gauge cluster would start up like normal but after a second every thing would go off again. I still was able to use power locks/windows and keyless entry. I have had the battery tested and alternator tested many times and it always comes back ok.
I have a jumper box with me since the last time. I put the jumper box on and the truck starts right up like nothing was wrong. I drive to the auto parts store, convince them that the battery is jacked and they replace it. Again truck starts fine. After doing some reasearch on here I think it may be a relay, only question is which one? Is there a main relay? Are they expensive? I don't know much about relays.

Thanks

 

To the Top.

Thanks

 

With all the checks you are doing, are both battery cables tight? Might not be the cause but it's something else to check. Good luck.

 

I have this same problem on my wifes 06 taurus. But the light will go off eventually but not like knight's does. It only started doing it when i had to jump her off. Took it to advance and the battery was bad. Thats when the light started coming on. I probed it and while its idling i get 13.5. Any ideas?

 

just because its providing over 12 volts does not mean that you have a good alternator. alternators have a habit of losing one or two of their three phases which will kill the output amperage.

Losing just one phase on your alternator you will probably never even notice.