M1097R1 Overcharge Issue Help

[Assault King]

Evening folks,
I will try to provide more detail or pictures if needed, I've never really tinkered with cars before but loved the humvee in the military.
I recently picked up my first humvee Monday. Fired right up. It's a M1097R1 with a 3 speed, and 6.5. It has what I believe is a 200 amp alternator with a dual voltage regulator atop labeled 14v / 28v. Upon sitting in the garage overnight with two good batteries, it drained both batteries to zero. I cleaned all of the connections, did a slow recharge on both batteries til full and put them back in. With the truck off, I can not hear any solenoids engage when the negative terminal is connected.
With the truck running, the trucks voltage gauge bottoms out in the overcharge. When I put a multimeter on the voltage regulator:
IGN to ground : 34 volts
AC to ground : 28 volts
Alternator positive cable to ground: 34 volts
14 volt to ground : 0 volts
Now I'm not sure if the batteries will drain again as I'm gonna give it a few hours and check again. I'm not sure what I have that's bad or if I have a parasitic draw. I'm a machinist, but electricity has always been rough for me. Cheers.

 

[Mogman]

Welcome to the SS forums, yep that is TOO high, it is normal to see 0V on the 14V tap unless it is connected to the 12V connection on the batteries.
Here is the troubleshooting guide.

 

[Assault King]

Welcome to the SS forums, yep that is TOO high, it is normal to see 0V on the 14V tap unless it is connected to the 12V connection on the batteries.
Here is the troubleshooting guide.

It's been a long hot week, thanks for taking the time to give input. I will check this out tomorrow afternoon and start running diagnostics. The whiteboard of issues continues to grow.

 

[Assault King]

Welcome to the SS forums, yep that is TOO high, it is normal to see 0V on the 14V tap unless it is connected to the 12V connection on the batteries.
Here is the troubleshooting guide.

So I feel as if I am getting some conflicting measurements when trying to prove if the alternator is defective or if the regulator is. Here were some quick measurements that I took,
Measuring bolt heads in battery box = 25 Volts
While truck is running the AC line on regulator = 15 Volts
Alternator measures = 34 Volts
Checking 4 pin cable going to regulator A and D = 3.1 Ohms
A pin to -B stud = OL
A pin to +B stud = 3 Ohms
With the regulator off, the alternator makes about 25 volts with the voltage gauge in the high side of yellow

 

[Mogman]

So I feel as if I am getting some conflicting measurements when trying to prove if the alternator is defective or if the regulator is. Here were some quick measurements that I took,
Measuring bolt heads in battery box = 25 Volts
While truck is running the AC line on regulator = 15 Volts
Alternator measures = 34 Volts
Checking 4 pin cable going to regulator A and D = 3.1 Ohms
A pin to -B stud = OL
A pin to +B stud = 3 Ohms
With the regulator off, the alternator makes about 25 volts with the voltage gauge in the high side of yellow

If you are reading 25V then the alt is not making anything, that is just the battery voltage.
99% of the time it is a regulator, the alternators are RARELY the problem, but of course you want to troubleshoot before spending money, throwing parts at a problem is never the answer.
You should have posted what the manual said the readings should be so everyone would not have to go and look everything up.
It is common to get (example) 3.1 ohms when the manual says (again just an example) 1.8-2.8 ohms due to lead loss in most meters.

 

[Mogman]

So I feel as if I am getting some conflicting measurements when trying to prove if the alternator is defective or if the regulator is. Here were some quick measurements that I took,
Measuring bolt heads in battery box = 25 Volts
While truck is running the AC line on regulator = 15 Volts
Alternator measures = 34 Volts
Checking 4 pin cable going to regulator A and D = 3.1 Ohms
A pin to -B stud = OL
A pin to +B stud = 3 Ohms
With the regulator off, the alternator makes about 25 volts with the voltage gauge in the high side of yellow

As I said earlier it is common to see a higher ohm reading such as you are getting from pin A to the B+ terminal, 3 ohms is close enough.
The measurement from A to D is also close enough, what do you get when you touch the red and black meter leads together? I would suspect it will not be zero ohms, if it is a cheap DMM it also will not likely measure low ohms with much accuracy, if there was an issue with the readings they would likely be way off to indicate an actual problem.
It looks like all your tests are pointing to a defective regulator.

 

[Assault King]

As I said earlier it is common to see a higher ohm reading such as you are getting from pin A to the B+ terminal, 3 ohms is close enough.
The measurement from A to D is also close enough, what do you get when you touch the red and black meter leads together? I would suspect it will not be zero ohms, if it is a cheap DMM it also will not likely measure low ohms with much accuracy, if there was an issue with the readings they would likely be way off to indicate an actual problem.
It looks like all your tests are pointing to a defective regulator.

Yeah you're right, posting what the diagnostic flowcharts say would have been the better thing to post along with the readings. I'll correct that in the future. As for touching the red and black meter leads together and see what that ohms out to.
I also found in the TM two pages on overcharging so I'm gonna check that our after work tomorrow before spending that much on a regulator.