Are these regulator brushes worn out? Upgrade from 95A to 130A with same serpentine belt?

[myf16]

The battery is discharging 9 amps while running, indicating an alternator failure.
I tried grounding the pin with no change.
So I removed the regulator and the brushes look a bit short.
Is it possible they are so worn out that they aren't making contact anymore?

Edit: I'm pretty sure these are nearly full length, so the problem is elsewhere.
I'm going to replace the alternator.
If I buy a 130A alternator the pulley is 59mm OD vs. 65mm for the 95A Delco I currently have.
Do I need to buy a shorter belt? The tensioner seems to be quite tight with the current 65mm pulley.
The belt is a 6PK2205 which is 84.4 inches long. We search says I should have 6PK2225 which is 87.6 inches.
So maybe the original Motorcraft alternator was 130A using the shorter belt.
Anyway, I'm comfortable keeping the current belt with a rebuilt 130A alternator.

 

[J_C]

Someone else will chime in and tell me if I'm right or not, but I think the shorter belt is for the 4.0L OHV engine and the longer for the 4.0L SOHC engine, and with the right belt for the engine, either alternator will work.

 

[C420sailor]

If you have a Motorcraft alt, rebuild it

 

[myf16]

If you have a Motorcraft alt, rebuild it

I bought a rebuilt motorcraft $90 on eBay. I’ll be back on the road next weekend.

 

[C420sailor]

If you don’t have to send in a core, rebuild your current one as a spare

Those OEM/MC alts are high quality

 

[myf16]

I'm embarrassed to report that my problem was not the alternator. I had pulled fuses in an unsuccessful attempt to locate a small current drain. When I re-inserted the "generator" fuse I missed the socket slightly. The fuse was slightly askew and not making contact. All's well that ends well.

 

[J_C]

So your alternator was working correctly after all, but you still have a (9A?) parasitic draw to track down?

Certainly some of the 9A figure mentioned, is going to be normal to operate the engine, dash, and more... not even counting if your HVAC blower, interior lights or headlights/etc are on.

You can measure the (milli-) voltage drop across the fuses to find suspect subcircuits, UNLESS you have generic fuses installed because they may have off-specification resistance values which result in too low a current measurement compared to actual current. Here is an example of measurements vs current:

https://www.meeknet.co.uk/E64/Fuse%20Voltage%20Readings%20To%20Give%20Current%20Readings.pdf

A web search will find more examples and there are some videos on youtube as well.

 

[allmyEXes]

I always assumed that OE alternators on Gen 2s were 130 amp but I just checked RA and I see OHV powered Explorers could have been factory equipped with a 95-amp alternator.
Once when swapping an alternator from a V-6 SOHC and my 5.0 I remember a pulley diameter difference. Maybe I assumed that the V-8 which runs lower rpms than the V-6 had the bigger pulley? I can't remember. In the past 6 or 7 years, I have had my hands on too many Explorers and I can't remember all of the details. I had a notebook that I was keeping up with repair details but it is currently misplaced. Maybe it will surface.