Brief "Check charging system" only in ignition

[NoManThankYou]

Hello,

I have recently purchased a used 2008 Explorer, the next day i was getting constant battery light and a "Check charging system" warning messages until the car stopped on the road.

I have replaced the alternator with a brand new one, so far it's working fine, but now i'm seeing the same warning message but only for a brief moment when i'm about to start the car (in ignition only), but when i start the car, i get no error messages or battery light.

i never paid attention if this message used to show up after changing the alternator, is that normal? or this message should not be shown at all times?

 

[tripplec]

You need a meter to check the battery voltage. Battery and/or connection my be bad. But normally it should NOT appear. Getting stranded isn't fun.

 

[NoManThankYou]

You need a meter to check the battery voltage. Battery and/or connection my be bad. But normally it should NOT appear. Getting stranded isn't fun.

Thanks for the reply!

Done, here are the results:

Engine off: 12.7 Volts
Running: 14.3 Volts

 

[tripplec]

Looks good at the battery. When off the battery should be at 12.5VDC or higher, too low could trigger a battery problem if its monitored.
Check between battery ground and the main buss connection of the Power Distribution fuse/relay box (should be a large connector bolted where it comes in). Also to chassis and body ground points. In case you have a poor vehicle ground which is due to corrosion (common on any vehicle over time).

Running volts: - Turn on head lights, then blower, then rear defogger etc The running volts should not drop below 14VDC. This is a loading test.

 

[plasticseng]

I had a similar problem on my wife's 08 with a 4.0. I found that one of the connectors on the alternator wasn't mated completely. It had no effect on the charging function, but the message center wasn't getting the reading it needed to confirm charging. Check all of your connectors for proper mating, and make sure no pins or sockets have pushed back.

It does seem kind of odd that it only happens when you first turn the key on. That message does not appear on hers at all.

 

[tripplec]

Yeah, its why I was thinking the battery voltage was too low but he confirmed it which is quite normal. Since the alternator was replaced it may be the thing to do and check the connection. Rush swap by the mechanic may have created the problem.

 

[azpima67]

All the warnings lights are supposed to illuminate after turning the key before the key reaches the point where it activates the starter.
You said " warning message but only for a brief moment when i'm about to start the car". So are the warning lights on at the same time?

 

[michael loibl]

Low charging output warning is normal with key on and engine off.
Bulb check mode is what it was called in the old days, lots of warnings should come on like oil pressure. They only relevant if they come on while engine is running

 

[plasticseng]

Low charging output warning is normal with key on and engine off.
Bulb check mode is what it was called in the old days, lots of warnings should come on like oil pressure. They only relevant if they come on while engine is running

I assumed he was talking about a warning on the message center, not just a bulb. All of the bulbs should light, but I don't think the warning in text should display on the message center.