MEP-805B no hrz/power readings

[Billy2642]

So I'll admit from the start, I'm not an electrical guru by any means. I've researched the TM and can't seem to find the issue. The issue I'm having is no hrz or power readout of any kind on the digital screen. Genset is a 2001 with version 1.1 onboard. I tried to excite the field by holding the start switch in the start position and no luck. Fuse under the panel doesn't appear blown. Switch is set to 60 hertz. I do have 1 red light under the panel as shown in the picture. Also, being the CIak screen the "heartbeat" light blinks green while running. I'm not jute sure how to tell if the generator is running at the full 1800rpm that it's supposed to. I've been told that rpm equal hertz but I would think it should still t least show something. Any tips for a newbie?

 

[Billy2642]

Also, if anyone lives near Yakima, wa and feels like coming to help me troubleshoot, I'll pay lol

 

[155mm]

Did you read thru this thread?

http://www.steelsoldiers.com/showthread.php?164332-2-MEP-805B-oh-the-joys&highlight=

 

[Billy2642]

Yes I had browsed thru that thread. I haven't experience and tried everything listed in it though. In my mind I was thinking a fuel issue so that's what I started with first. In the mentioned thread above, how many o rings for the fuel system have to be replaced and where are they? I started at the injection pump ad unmediated found something that seemed wonky so I took pictures. Instead of the line being flanged like I thought it would be, it had some sort of rubber type flange. Is this normal? It obviously needs replaced but just doesn't seem as efficient in keeping air out and whatnot as if the metal line itself was flanged and coupled with an oring. Hopefully the dealer has this rubber part if it's supposed to be this way

 

[155mm]

That fuel line should be flared, and I bet that the collar is cracked, if not cracked it is spread out so much that it bottoms out on the nipple it skrews on.

If it were me, I would replace the nipple that skrews into the pump, the collar, and the rubber washer. And flare that fuel line. I will try to find the pn for the rubber washers, there are 2 different sizes. Any time you take a fuel fitting loose, inspect that washer, if it even looks a little bit used, replace it. The 85 cents is worth it when you have been chasing a no fuel issue for 2 days. Also if the rubber is bulged out the collar, change it.

If you need a good nipple to take to the parts store, there is another one on the fuel filter that is the same.

 

[155mm]

Jd pn for inj lines, r79605

jd pn for fuel line washer, r51936

 

[Billy2642]

That fuel line should be flared, and I bet that the collar is cracked, if not cracked it is spread out so much that it bottoms out on the nipple it skrews on.

If it were me, I would replace the nipple that skrews into the pump, the collar, and the rubber washer. And flare that fuel line. I will try to find the pn for the rubber washers, there are 2 different sizes. Any time you take a fuel fitting loose, inspect that washer, if it even looks a little bit used, replace it. The 85 cents is worth it when you have been chasing a no fuel issue for 2 days. Also if the rubber is bulged out the collar, change it.

If you need a good nipple to take to the parts store, there is another one on the fuel filter that is the same.

So I went to John Deere on my lunch break and showed them the pictures. We looked up the schematics and sure enough, there is no flare on the end of the line. The rubber seal basically looks like a small piece of cut fuel line that slides over the steel fuel like and then compresses/clamps/seals as that brass nut is tightened. Doesn't seem like a very good design and even the guy at the parts counter agreed. Hopefully I can get this back together tonight, prime it, and see if this helps anything

 

[155mm]

I have worked on 4 of these so far, and everyone of them needed a new collar, and every one of them had a flared end that had to be cut off to replace the collar, and it got reflared after the new collar went on.

 

[Billy2642]

I have worked on 4 of these so far, and everyone of them needed a new collar, and every one of them had a flared end that had to be cut off to replace the collar, and it got reflared after the new collar went on.

That's really odd. What year were they by chance? I know the 806B is like that. I ordered a whole new line just because this one looked a little worn anyway. I should receive it Thursday.

 

[Guyfang]

So I'll admit from the start, I'm not an electrical guru by any means. I've researched the TM and can't seem to find the issue. The issue I'm having is no hrz or power readout of any kind on the digital screen. Genset is a 2001 with version 1.1 onboard. I tried to excite the field by holding the start switch in the start position and no luck. Fuse under the panel doesn't appear blown. Switch is set to 60 hertz. I do have 1 red light under the panel as shown in the picture. Also, being the CIak screen the "heartbeat" light blinks green while running. I'm not jute sure how to tell if the generator is running at the full 1800rpm that it's supposed to. I've been told that rpm equal hertz but I would think it should still t least show something. Any tips for a newbie?

When you get it back together, and if you still have no hertz an no volts, turn on the gen set. Flip the AC contactor switch to ON. Measure at the output load terminals. Then at TB1. Can't tell you the wire numbers, as I am using a tablet. But look at the schematics. You can figure it out. You want the wires from TB1 to the output contractor. Or take the shield off the input side of CB1 output contractor. Then measure AC voltage. Take care when you have your knobdickers in there. There is a reason TB1 has plastic shield on it.

 

[155mm]

What year were they by chance?

Early to mid 2000's, Marine Corp versions, that shouldn't make any difference on what kind of fuel line was used.

 

[Billy2642]

So I got the fuel lines back together and it definitely runs smoother. As far as testing different things, I think I'll be better off taking it a gen shop and paying the $60 for them to diag it versus me getting my hands in there to electrocute myself. I can't imagine that with only 2000 hours the generator head is bad. I also don't know for sure if it's running at 1800rpms which is the first thing they will check. Could something simple like a bad master start switch be the culprit?

 

[Guyfang]

I need to ask some questions here.

Is this set new to you?
Have you ever seen it work right?
Do you have the TM's for it.
Have you read the Troubleshooting?
Do you have basic tools and a multimeter?

You don't have to be afraid of this beast. It won't bite you unless you do something stupid. So before you give this thing to someone else who has never seen one before, give it a try yourself.

 

[155mm]

I agree with Guy, figure this out yourself. What are you going to do in a snowstorm when it quits? Its only been a couple days, and most of that time is spend on making it run.

 

[Billy2642]

Well it seems all signs point to the voltage regulator (AVR100). It seems I read a thread in this site about them not be grounded thru the mounting screws or something like that. Anyone have any tips on saving this voltage regulator before I buy another? Also, are the voltage regulators the same between 804b, 805b and 806b?

 

[Guyfang]

Well it seems all signs point to the voltage regulator (AVR100). It seems I read a thread in this site about them not be grounded thru the mounting screws or something like that. Anyone have any tips on saving this voltage regulator before I buy another? Also, are the voltage regulators the same between 804b, 805b and 806b?

Using the part number AVR100 will bring you nothing. It's always a good idea to use the NSN when looking for parts, or give both numbers. In any case, AVR100 is not listed in the military system. In the back of the TM, is a listing that converts the part number into a NSN. Its called: CROSS- REFERENCE-INDEXES PART NUMBER INDEX.

The AVR100 part number, Figure 5, Item 61, with a UOC of LTX, gives the NSN: 6110-01-470-4253. That is the correct NSN for the Volt regulator.

No, the volt regulator is not compatible with the MEP-804A. There is no such thing as an MEP-804B.

Yes the Volt regulator is compatible between the MEP-805B and MEP-806B.

I wish you luck in your repairs.

 

[Billy2642]

Using the part number AVR100 will bring you nothing. It's always a good idea to use the NSN when looking for parts, or give both numbers. In any case, AVR100 is not listed in the military system. In the back of the TM, is a listing that converts the part number into a NSN. Its called: CROSS- REFERENCE-INDEXES PART NUMBER INDEX.

The AVR100 part number, Figure 5, Item 61, with a UOC of LTX, gives the NSN: 6110-01-470-4253. That is the correct NSN for the Volt regulator.

No, the volt regulator is not compatible with the MEP-804A. There is no such thing as an MEP-804B.

Yes the Volt regulator is compatible between the MEP-805B and MEP-806B.

I wish you luck in your repairs.

im hoping to get some time this afternoon to take it off the wall, clean the connections, and remount and pray that I get lucky. New ones are hard to find it seems. Anyone have one laying around? I'm wondering if they can be rebuilt by a shop for a reasonable rate.

 

[Billy2642]

Have you guys ever heard of or had any luck with "re-energizing the field"? I've been reading that if a generator sits for long periods that it can lose its magnetic charge and has to be reengerized. The jist of it says to take a cord with a male plug an

 

[Billy2642]

Have you guys ever heard of or had any luck with "re-energizing the field"? I've been reading that if a generator sits for long periods that it can lose its magnetic charge and has to be reengerized. The jist of it says to take a cord with a male plug on each end and plug one end into a known good power source like your house or another generator and the other into the dead generator while it is running and this should reenergize the magnetic field. Has anyone tried this?

 

[DieselAddict]

That is what the "field flash" feature does as part of the unit starting up. When you hold the main switch in the "start" position that flashes the field to magnetize the alternator.

If you have a unit that makes power when starting but doesn't make power when you release the start switch its the field flash circuit that is causing the unit to make power while starting.

What you are describing would only be necessary for a self excited alternator like what you buy from your big box home store. These aint those (I'm southern).