Battery light flicker - intermittent

[Number4]

My battery light comes on for less than a second every so often. Looking at my Ultra-Gauge (which is set to PCM voltage) it runs 13.90-14.07. But, it'll go up to 14.40 and down as far as 13.23 on occasion.

The light doesn't seem to come on with any particular voltage.
Just a moment ago, the Ex started to run weird and the radio flickered.
PCM voltage showed 17.??.

So I put my multi meter on the alt. lug and the battery negative.
It read 13.9 - 14.07 and did not vary outside that at all.

So I went back to my Ultra-Gauge and set it up to show PCM voltage as well as Ultra-Gauge voltage.

The Ultra-Gauge voltage was spot on with the multi meter.
The PCM voltage was still going haywire.

So even though the alternator is charging perfectly fine, the PCM reads otherwise and impacts drivability.

I'm going to pull pin 24 on the PCM connector and look for corrosion, but was wondering if anyone else had come across this.

Also, not sure how the Ultra-Gauge can get a different reading than PCM voltage as it comes through the PCM.

 

[plasticseng]

I had something similar on an '08. Thread attached.

http://www.explorerforum.com/forums/showthread.php?t=360467

 

[Number4]

I had something similar on an '08. Thread attached.

http://www.explorerforum.com/forums/showthread.php?t=360467

Lol - I love how these become off topic arguments. I believe my fix was similar, will post what I did, which was just a little more in depth, but basically same thing.

For the record, here is information out of a JCI Battery catalog on voltage vs state of charge. JCI makes all the batteries for NAPA and maybe Interstate, maybe.

 

[Number4]

How I fixed my issue

From the alternator, there are three connections to the PCM.

1. At the alternator itself
2. Connector right beside the battery
3. At the PCM

Pulling the PCM connector revealed what looked like gold plated connectors. None of which had any signs of corrosion. Most likely not my problem.

So I pulled apart the connector at the battery. The pin here is a bullet style connector and it looked okay. I did not disassemble this connector but using a small flat head screw driver (think eyeglass repair tools) I did scrape the pin, hopefully cutting through any unseen corrosion.

Then I went back to the alternators connector, it was a little loose, but the connector pins seemed to be corroded, just a little. So I disassembled the connector, cleaned the pins and reassembled it. After doing so, my battery light stopped flickering and the voltage on my Ultra-Gauge returned to normal.

Disassembling Ford connectors is fairly easy once you've done a few. They will usually have a reddish colored plastic piece in them. This piece serves as a locking mechanism. Removing this piece is a little different on each connector. In this case, you simply leverage it out from the holes for the pins. This was an easy one.

Now, the pins themselves are always held in place via a plastic 'tong' that catches a slot on the pin itself. You must release this catch, which will allow the pin to be pulled out via the back.

Once the pin is out (and I removed both) you can remove the 'rubber' moister plug and go ahead and clean up the entire connector. I recommend taking a picture of the connector so you will remember which direction the pins went in and on which side.

In two of the pictures, I'm showing the connector housing empty, so you can see the plastic tongs which keep the pins in and how I depressed them with the tiny screw driver tool.

All said and done, vehicle runs fine again. This only became an issue a week or so after replacing my alternator. I figured it wasn't the alternator and was able to verify it was charging properly even though the Ultra-Gauge was getting bad readings. Interestingly enough, because the signal to the PCM was "bad" the car was starting to have issues.