diagnosing battery light (charging system)

[Petesexpy]

Hi All. I have been battling a battery (charging system) warning light. Battery and alternator check good. Diagnostic points to bad ground, but I cleaned all ground connections. What's left are cables themselves and possibly the BCM. Any thoughts how I can test those?
Or any other ideas?
UPDATE
Cleaned and replaced when needed ground straps. No change. Engine running rough with not codes. UGH.

 

[Kevmobile]

Testing Non PCM Controlled Alternators On Ford Vehicles

In this video I go over a few simple test to see why your alternator is not charging.

youtu.be

FTM has a good video on this. He mentions unplugging the connector on the alternator and checking if the battery light changes.

I ended up having to replace my voltage regulator.

The alternator grounds thru the engine block. So does the starter, check resistance of engine ground.

 

[Petesexpy]

Testing Non PCM Controlled Alternators On Ford Vehicles

In this video I go over a few simple test to see why your alternator is not charging.

youtu.be

FTM has a good video on this. He mentions unplugging the connector on the alternator and checking if the battery light changes.

I ended up having to replace my voltage regulator.

The alternator grounds thru the engine block. So does the starter, check resistance of engine ground.

I did 3 checks unplugging things and everything points to the ground (voltage is steady). I cleaned grounds on the firewall (passenger side). Where is the engine ground?

 

[Billme]

Here is mine on the firewall.. It goes to the rear of the passenger side head where the return heater to pump line bolts to..It’s half inch braided strap..

 

[Petesexpy]

Here is mine on the firewall.. It goes to the rear of the passenger side head where the return heater to pump line bolts to..It’s half inch braided strap..

OK, I got it. Is there a ground strap I can replace it with ? I only found generic ground straps. Also, I read there is body-to-frame strap under the passenger front door?

 

[Billme]

As for as replacing, the engine ground, it is very hard to get to on the back of the head. I would just add it to the firewall original point, and the other end on the manifold.. Mine is working good there..
As for as the body to frame ground, mine is on the driver side towards the rear..
I not sure, but there may be more than one..Should be easy to find since it’s a braided strap..
When I done my timing chain job, when I put the intake manifold back on, and forgot to add the ground strap to the return heater pipe to pump mount.. Noway to reach it for me, so I mounted it there..I originally had it behind the alternator, but didn’t like it there.
You can get another strap at a salvage yard easy

 

[Kevmobile]

Check resistance from your engine block to ground at battery. Do the same for your chasis. I would wager you need a new voltage regulator if you are not in a northern climate (rust)

 

[Petesexpy]

Check resistance from your engine block to ground at battery. Do the same for your chasis. I would wager you need a new voltage regulator if you are not in a northern climate (rust)

I'm in Delaware. I decided to replace most ground straps. The voltage is steady as a rock and the alternator is 18 month and 6K miles old.