Checking Charging System

[sumo509]

Hi, all. First of all I just wanted to say thank you in advance for anybody who can come up with any answers or has any advice whatsoever. Also, I apologize for the novel and if there are spelling errors because I used talk-to-text.

TL;DR... checking charging system error started happening intermittently, Explorer completely died while driving, replaced battery because I figured why not, turns on but same check charging system light/beep persists, and battery discharges when running.

A few nights ago I was driving around and the check charging system light flickered a few times mostly when I came to a stop. It stopped while I was heading back home so I figured it wasn’t really a big deal.

This made me remember a few weeks back my son had been playing in the Explorer and that caused a dead battery because he left the lights on overnight. The next day I jumped it, let it charge and everything was fine for a few weeks until this started happening. (doubting there’s a correlation..)

Back to the day that this occurred... later that night I was going to and almost instantly it started beeping. It only beeped a couple times so I figured it would be all right to make the trip seeing as how it was only like a 20 minute round-trip. Boy was I wrong...

We made it to Walmart just fine I don’t recall it beeping too much-although I was still concerned. On the way back I can’t recall what went first but essentially the headlights went out the dash went out radio went out etc. etc. until finally the vehicle just plain stopped.

Not knowing what the problem was I called a tow truck and had it towed to my house. I started by testing the battery and it read 8.xx. I went ahead and got a new battery—why I didn’t try to jump/charge the old one, I don’t know. It’s probably still salvageable for all I know but whatever. I figured if $70 would fix my problem, awesome. Obviously it didn’t.

Today I finally replaced the battery and the car would turn over. Bad news is, the check charging system light issue persists. For some reason I figured if I left it on for a while with a new battery that maybe it would somehow fix itself. This was obviously not the case because I checked the voltage on the battery while running and it was draining.

Just some minor details... the positive terminal did have a lot of acid build up so I went ahead and took care of that with battery cleaner and protector when I swapped the battery. Everything looked a little bit better but the positive terminal does still have a little crud on it. (Wondering if this is/was the issue all along... will try a deeper clean tomorrow.)

Lastly, I did a lot of research and saw things about the harmonic balancer, fusible links, and checking the alternator connections. The only thing I’m really able to do with my mechanical knowledge (which is very minimal) was check the alternator connections which looked fine to my untrained eye.

I really don’t know what to do at this point other than to take it in to get looked at. I would really just like some advice on what to ask them to look for so that way I don’t get screwed over for some minor fix. I also know I should have the alternator tested—which I plan on doing prior to going to a mechanic assuming it doesn’t die again along the way.

Thanks again!
Chuck

 

[Rick]

Not only do the terminals corrode but the cable itself can corrode internally. If the cable seems swollen under the plastic insulation, replace it/them.

You can have the alternator checked at most autoparts stores.

 

[Slimpete17]

I’m having the same issue. I’m thinking it might be the cable but I replaced the battery, the problem persisted so I replaced the alternator. Problem went away for about a week and then the code popped again while I was driving. It’s ONLY at low speeds though, Highway it does fine for at least a little while. I don’t have the car with me, it’s in Hawaii and I’m in PA so...

I can’t wait to figure it out and get back to driving.

 

[Sereno011]

TLDR: It was the Alternator

Was also dealing with the "Check Charging System" popping up intermittently on my 03 Mounty (4.6L). But also frequently. Wasn't charging weakly, putting out plenty of voltage and amperage. The charging was just cutting out. And oddly the message would only pop up after I started moving. Never at initial idle and could rev all I wanted in Park. But drive 50' and there was no pattern to the symptom.

First tried swapping the voltage regulator (had a spare on hand) that made no difference. Verified wire integrity to the VR and pin fitment was snug. Checking all the grounds, even had the ignition switch apart. (Do NOT attempt that. Switch is actually robust, unlike a Chrysler, but a PIA to put back together). Was nearly about to tear apart the power distribution box to look for the green crusties. For a 20 yr old NE (salt belt) vehicle all the exposed ground terminals are still pretty pristine. Also tried swapped the PCM and A/C clutch diodes. A Hail Mary but worth a shot.

But in the end problem did turn out to be the Alt. AGAIN! Seem to only get maybe 2 years out of them (on my third now). But the way this last one failed was unusual. Seen them totally fail and even some shorted ones over the years. But can only assume the rectifier bridge this time was intermittently shorting. I know I should stop putting in remans but never expected the truck to last this long (@315K now). It's a Ford so stupid problems keep popping up. Terrible MPG and rocker panels are MIA. But frame is solid and she just will not go quiet into the night.

I was also having an issue of truck just dying out completely while driving. Just stalls and anything electrical goes dark. But usually after a number of frantic key cycles and waiting a few moments all comes back to life, restarts fine and can continue on. Thankfully this was far more rare, though making it even more difficult to diag. I'll admit one batt terminal wasn't snug as it should be and did find a light amount of carbon buildup. Though always cranked over strong. So still unsure if that symptom was also from the suspected shorting Alt or the poor batt connection.