Have a 05 Explorer, and it intermittently gives a message to check charging system, and the red battery light comes on the instrument panel. The charging system works OK, put out around 14.4, 14.5 volts when running, and checking with a meter. Put a new alternator on it around three or so months ago, it had quit charging. Now this message comes up at different times. The battery was a few years old, and the charge would drop down overnite to just over 10 volts, so I replaced the battery. But the message returns, usually after the vehicle is driven a distance. The instrument panel has a voltmeter, that just reads H-L, and it stays in the mid range, and has not been noticed moving around. I was wondering if anyone else had experienced this issue and what might be the culprit?
Thanks Terry

 

Thread moved to the appropriate forum for an '05 Explorer

I've attached a piece of the EVTM for the 2001 Explorer, just so we know what we're dealing with. The 2005 is a bit more advanced with the dash electronics, apparently, but for now, let's use this.

The "battery light" is fed by a direct output from the regulator that is mounted on the alternator. The regulator itself is somehow detecting a problem. Do your headlights flicker, even a little bit, at idle when it's nice and warmed up?

 

First of all, sorry my original post was on the wrong forum, wasnt' sure where to post it. Now I know. Thanks Krewat for you reply and info. I got with my brother, who actually makes a living as an auto technician, even though it is on European cars. We took and checked and cleaned all the grounds. He said the connector that attached the wires to the alternator, one of the pins did not look correct, (bent), this probably came about when I changed out the alternator 3 months or so ago. After we did these items, the light has not come back on, nor received the check charging system message again? I guess it could have been either one of those that cleared up the problem, or at least for now. Thanks Terry

 

Nice, thanks for reporting back

 

Well, I am back, and so is the problem. The message check charging system, and the red battery light have been coming and going intermittently for some time now. This is wife's vehicle and she has mentioned this a time or two over the last several months. I keep checking the voltage with the engine running, and it's still good, over 14. Now she has been reminding me more often, since the message and light are staying around a lot longer, in fact, currently they are steady. The connector I referred to above, has the three wires that connect to alternator, and the same color code. I may have to try and replace the connector, I checked earlier today, it is available at auto zone, and o'rileys. I had forgotten that I started this post or whatever you call it back in April, but it popped up when doing a search. I was going to check and see if anyone else had this problem that could enlighten me on my journey? From what my simple mind can deduce from the electrical drawing above, looks like light green/red wire sends a signal to the instrument cluster, not too sure about how or what the yellow wire from the central junction box to the cluster is for, or what it does? I am open for being taught how this is supposed to work? Thanks for any help I can get. Terry

 

This would happen to me and I’d wiggle the wire connector and it’d be fine for some time.

I eventually spliced in a new connector and it solved the issue.

I run and UltraGauge OBD II reader and saw that the battery voltage was fine, but the ECM voltage would fluctuate. Basically, the signal to the ECM was bad due to the connector. This isn’t good as the ECM uses this signal to determine how the alternator charges.

 

Thanks for the reply number 4! I have found a couple threads or whatever you call them, and people were having the exact same issue as myself. But never saw as to what "they" did to fix them? Kind of like reading a story, and it ends before the finish? I have been debating getting a new connector, or taking the alternator back to Auto zone for a test, or what? The connector did not look like it should have any issues, but who knows? This is my first trip down the road of the ecm having anything to do with charging voltage. All the testing of the older stuff, if battery voltage went up during engine running, it is charging, and end of story. I will have to see if my scanner will show voltage at the ecm? Part of my problem, is getting the explorer to sit still long enough to investigate. Four other trucks, and a Town Car, and (all Fords) her car the explorer burns the road up? I will try some more checks as to your experience, and will report back as I can. Thanks again for the reply, as we all know, experience can be costly.

 

We call that "reporting back".

 

Well, I am going to try and give a report back. It has been a few days, and have been reluctant to report back. I went to the Zone, and got a new connector, and spliced it in. Cranked up, and still getting the check charging system message, and red battery light coming on. Checked voltage at battery, and still getting 14.4, with engine running. Drove it four miles to check on my elderly mom. As I arrived there, steam pouring out from under the hood. Heater control valve port broke off. After checking on mom, drove it the four miles back home, and no message, and on battery light. Pulled it back into my shop, and went next day and got new heater control valve, and had to put two gallons of coolant in it. Drove about eight miles to visit brother at his shop, and ensure no other coolant leaks. No message, no light. Drove back home, and about halfway there, the message and light came on for a brief period. Come on once more on the rest of the way home. Drove around some more next day, and once, or twice, message, and light came on briefly. Told wife if she drives it, to only do short trips, wheel bearing is now starting to announce that it needs attention. Bought new bearing today, and will replace in next day or two. She says the message, and light have not came back on during the couple short trips she has been on. So at this time, the message, and light have gone from coming on, and staying on almost continuously, to some brief instances. It is better, but I can't call it repaired completely at this time? We will soldier on, and see what happens. By the way, the pin broke on camshaft gear, and engine locked up at 165K, put in rebuilt from Rock Auto, tranny went out at 185K, had it rebuilt, and doing good. Now has 200K on it, and hopefully will go for another 100K or so. Love hurts. Good night John Boy, and Mary Ellen, life can be hard on the mountain.

 

Well, it has been sometime since I reported back on this issue. The chime got so frequent from the check charging system that the wife did not even want to drive the Explorer. I understand, the couple times I drove it, it almost pushed me over the edge. Maybe month and half or so ago, I went to investigate this problem again. Checked the voltage, and it was running over 17 volts, when idling. Took off the alternator, and took it to the Zone where it is still under lifetime warranty. Then ran test on it about 5 or more times, all OK. Said a few expletives, and put it back on. Drove to brothers shop.Asked him to put his meter on it for comparison.14.4 volts. My battery needs replacing in my meter! No problem, been wanting to run test on alternator to verify it. Went back home. Decided to check grounds again. The main ground from negative battery cable goes to one of the bolts on the starter. I took that off, had some oily residue on it, cleaned with brake cleaner. Tested, no light, no message, and they have not come back since. It seems during the initial testing, cleaning of the grounds, my nephew who is much more agile than myself who was doing the cleaning testing, did not do the main ground. He is19, and knows more than Websters, still gotta love them. After two months or somewhere around there, the issue has not come back. And if it does after posting this, I may never post again? Now if I just figure out why every time I get in the vehicle, the gas gauge reads on E, and usually with the fuel light on? I think I just felt the knowingly nodding of several heads upon reading this. Happy trails, and may they all lead back home. Terry