MEP-804b no voltage/hz issue

Which particular tm do I need. I will do them all but not at this moment.

Well, let me ask some questions. It helps us know how to go about helping you.

Is this set new to you?
Have you ever seen it work right?
Were you working on it and it quit functioning?
Have you used a TM before?
Can you get along in a schmatic a little bit?
Do you have a multimeter?

If you are new to this gen set, and have never operated one like it before, then start with the TM 9-6115-643-10, operator's manual. Get smart on the basic operation of the set. If you are comfortable with TMs, and know this gen set well, then download the TM 9-6115-643-24, and we can start looking at the troubleshooting and problem.

Oh, If it takes me a bit to get back to you, I am 6-7 time zones out of sync with you, so have a little patience.

Yes, the gen set is new to me. Just got the engine running today( was missing a few things). But have a low voltage light. Also the test and reset breaker not working( or think it’s not working - doesn’t reset or click off) I’m not so good with the schematic. However my father is helping me and he is an old c-130 mechanic/ retired master chief. He understands military manuals for sure( all else fails read the directions is what he says) Do have a meter. Just printed off the operation manual. Thumbed through it a bit. Will print off the other one now. As for you getting back to me it happens when it happens. Just really appreciate the fact you are willing to help.


V/R

Chris Pope

Chris,

I need to know what you are calling Test and Reset Breaker. I am going to guess its the A2, Malfunction Indicator, (Fault Indicator or Idiot lights). If I am wrong, let me know. That's one good reason to look at the -10 manual. It explains what the things are, what they do and what we call them. It keeps us both on the same sheet of music.

Ok, set runs, but no voltage. The first thing you need to do is tell me if you held up the start switch long enough. You can not get the starter to clash, if you hold it up too long. If it does grind, tell me. The whole TQG family of gen sets need to have the starter engaged longer than most people feel good about holding it up. So the next time you start it, hold the S1 Start Switch up at least 6-8 seconds. At least.

I also need you to take a picture of behind the control panel. Post it in a message back to me. If you have a problem doing that, let me know. I will try and walk you through it. I need the picture to see if there is a fuse installed there. It's a MWO, Modification Work Order. It won't even be on the schematic. Its important to protect the G1, Main Generator. If its missing, or bad, you will not get voltage.

Tell the Master Chief, from one Chief to another, Greetings and Salutations! Happy Vets day!

Yes the ground fault circuit interrupter. It will take a bit to pick up the lingo but I will at least go look it up to make sure I’m calling it the same thing( see where it can cause problems). Did start it and held the master switch that starts the unit for 8 secs and realized that the voltage meter and hertz meter were showing voltage. The ground fault circuit interrupter does work. Not sure how to post these pics though.

Open the control panel. Look to the left. On the side of the CB3, Ground Fault Interrupter is a small switch. Not on the cover, on the side of the box inside the control panel. Its hard to see. Its a small switch. Press it, and the CB3 is reset.

When you let the S1 go, does the volts and hertz meters still read?

Guyfang said:

Open the control panel. Look to the left. On the side of the CB3, Ground Fault Interrupter is a small switch. Not on the cover, on the side of the box inside the control panel. Its hard to see. Its a small switch. Press it, and the CB3 is reset.

When you let the S1 go, does the volts and hertz meters still read?

Click to expand...

Cb3 did not need to be reset. When you release the s1 the light comes ( low voltage light). on and the needle drops to nothing.

Cb3 did not need to be reset. When you release s1 the light goes out and the needle drops to nothing.

Light come on low voltage.

But the volts and hertz came on as long as you hold up the S1?

Yes

Start the set up, hold S1 up, turn on the S7 Battle Short and let go of the S1. What happens?

Needle drops to nothing

Its getting late here. 24:30. So we can try one more thing, then this old soldier needs some beauty sleep. Behind the control panel, on the right side, on the bulkhead, is the A1, Volt Regulator. Is there a fuse directly to the left of the A1? If so, check it with a multimeter to see if its good. That what I wanted to see a picture of.

We checked it earlier and dad said it was good but will double check it in the am. Thank you for your time. Get your rest and happy vets day! And thank you for your service!

You all take care also!! Happy vets day right back at you!!!!!!!!!!

I have the same issue. I'm thinking it's the voltage regulator. I have a new one that's being delivered tomorrow so I'll update on if that works

Okay great! Where do you find a voltage regulator?

Morning!

The Volt Reg is in the control panel. It has the A1 written next to it. Right side of the balkhead.

Open your -24 manual to PDF reader page 393. There is the start of the troubleshooting for GENERATOR SET FAILS TO GENERATE POWER:

For the first step, testing the A5 governor, go to PDF reader page 442. Simple test. Do only step 4-2.1

Next, go back to page 393 and read step 2. The A1, AC volt regulator test. Go to page PDF page 437. Here is where it gets tricky. Look at the PART NUMBER of the volt regulator. There is two different types. Two different tests for the regulators. Find the part number, find the proper test for your regulator.

Please tell me the name of the manufacturer listed on the volt reg.

Also, before you even start all of this, Check the MPU, Magnetic Pick up. Go to PDF reader page 366. Read the whole deal about the MPU. Its really simple. And you don't have to go through the whole nut roll that's in the TM. The simple way is to disconnect the two wires. take a multimeter and set it for AC VOLTAGE, (yes AC) and hold it on the two leads that go to the MPU. Have your Father turn the set over with the S10, Dead Crank Switch. You should get between 2.5 and 3 volts AC. The closer to 3 volts, the better. I would pull the MPU and check the end of it, to see if its even there. It happens. But if you get a good reading, don't fool with it.

Guy,

I think I have located the 804a voltage regulator. How many people on this site would you guess are currently looking for it?

Part# 19870
NSN # 6110-01-368-7123

Got an email into them to see how many they have or can get. They like them an awful lot. The price tag is roughly 705.00 each not including shipping.

Chris..