mep 803a stopped on its own, wont turn over via main switch, has battery power

[Gunny65]

Had a power outage last night. Turned 803A on, switched house power to genset power. It ran fine for 5 hours. Then there was a VERY short power fluctuation. Woke me up as my A/C unit beeped during the fluctuation. I went outside and the genset was running fine. No stuttering, nothing. I opened the front panel, went to turn the main switch to off and just as I was getting ready to turn it off, it went off on its own. Oh, and all the fire sensors in the house went off right before the genset died. (No, no fires. The sensors are hard wired into the house electrical system. I didn't and don't see any fault lights on the genset when I went to turn it off and after when I tried to start it up again. When I turn the main switch to prime it sends power to the pump, you can hear it fine, sounds normal and all, but, when I turn it to start, nothing. No click, nothing. I tried the dead switch just to see, it makes a sound but no cranking. The oil was at the low mark. After going over everything, checking fuzes, reseting switches, etc the low oil was the only thing I noticed that is was not quite right. The oil showed on the stick but on the low mark of the dip stick. That is the only thing I can see that was wrong.

Is there a low oil reset switch somewhere? Assuming it was low oil that shut the genset down. Suggestions? I am adding to this as I try troubleshooting steps.

So the short of it is. S1 will not crank engine. S1 prime is working, I can hear it kick on. Tried battle short, no help. Tried dead crank, no crank. Batteries are full and do not seem to be draining. Filled oil to full line. Checked coolant, is good. Power is there but no action. Emergency stop is out.

 

[Light in the Dark]

Do you have any fault lights?

 

[Gunny65]

Do you have any fault lights?

Nope, didn't notice any when I went to shut it down and don't see any when I turn s1 to prime/run.

 

[Zed254]

You did not indicate if you added oil back to proper level. If not, do it and then attempt a restart. There is a low oil light on these units.
From TM
SYMPTOM
10. Low oil pressure.
TEST OR INSPECTION
Step 1. Check for low lubrication oil level.
CORRECTIVE ACTION
If necessary add oil, refer to LO 9-6115-642-12.
TEST OR INSPECTION
Step 2. Check for high coolant temperature, above 200 °F (93 °C), refer to WP 0004, Table 1, Item
3.
CORRECTIVE ACTION
If coolant temperature is high, go to Step 3.
TEST OR INSPECTION
Step 3. Check coolant level. If low, add coolant, refer to WP 0015, Servicing.
CORRECTIVE ACTION
If full, go to Step 4.
TEST OR INSPECTION
Step 4. Check for obstruction in air intake system.
CORRECTIVE ACTION
If obstructions are found, remove debris. If no obstructions are found, go to Step 5.
TEST OR INSPECTION
Step 5. Check for loose fan belt.
CORRECTIVE ACTION
If loose, notify next higher maintenance level.

 

[Gunny65]

I have now lost three replies. Power keeps going out. Yes, followed chapter 3, troubleshooting guide. Looked through LP TM. Yes, I did fill the oil back to full. Did check coolant level, is good.

 

[Gunny65]

TM 9-6115-642-10, Chap 3, Operator Troubleshooting Procedures

 

[Gunny65]

Sorry for short, quick replies. I have been trying to do this via the TMs I have downloaded since I have been without power for most of the day and night. Power keeps going off and on now. NO internet with no local power.

 

[Zed254]

I would check fuses and look for a bad wire connection / short. Low oil may or may not be involved in shutdown. If oil, should have had the oil light on....and confirm plenty of fuel in tank.

 

[Gunny65]

I would check fuses and look for a bad wire connection / short. Low oil may or may not be involved in shutdown. If oil, should have had the oil light on....and confirm plenty of fuel in tank.

Yes, fuel is a 3/4 tank. Checked via gauge and visual. I did a basic check of wires and fuzes. Didn't see anything loose, missing, burnt, or fuzes popped or burnt.

 

[Gunny65]

I just checked battery levels with multimeter. One is 8.9 and one is 7.8. Is it possible my alternator went out and the genset ran until the batteries could no longer support the draw any longer? Not sure if that is possible. ??

I checked the belt and it is in great shape. The engine was overhauled in 2010 about 270 hours ago. The alternator does not look as good as the engine. I assume it is the original. The dead switch makes a single clank sound and then nothing. S1, again, does not even do that.

 

[Guyfang]

From your first post, I would have told you to check battery voltage. You do not have enough battery voltage to turn the set over. So first, check the battery charging circuit fuse. Use a multimeter. Then change or charge the battery's. Once you get the battery's charged, you should be able to start it. Then check to see if it's charging.

 

[Gunny65]

From your first post, I would have told you to check battery voltage. You do not have enough battery voltage to turn the set over. So first, check the battery charging circuit fuse. Use a multimeter. Then change or charge the battery's. Once you get the battery's charged, you should be able to start it. Then check to see if it's charging.

Looking over the multi colored circuit diagram I downloaded from this forum, I don't see where the battery charging circuit fuse is located. Right now my mind is half burned out so I am probably just missing it. Pointers?

 

[Zed254]

FU1, behind control panel. TM 9-6115-642-10 figure 0004-1, item 21.

 

[Gunny65]

FU1, behind control panel. TM 9-6115-642-10 figure 0004-1, item 21.

Ah, okay. Got it. For future people. TM 9-6115-642-10, page 0004-1, figure 1, #21. It is a regular glass tube fuze behind the control panel. NOT being a jerk, Zed254. You got me there. Thank you!!

BTW, the fuse is good.

 

[Gunny65]

Looks like there is a regulator on the back. I found one exact match. It is in Guam. Joy.

I tried for replacement parts but my **** power keeps going out and I lose my links. Does anyone know a good place to purchase this? I can find the basic alternator LR220-24 but not with a regulator. Haven't found a regulator replacement either.

Any help would be appreciated.

 

[Gunny65]

From your first post, I would have told you to check battery voltage. You do not have enough battery voltage to turn the set over. So first, check the battery charging circuit fuse. Use a multimeter. Then change or charge the battery's. Once you get the battery's charged, you should be able to start it. Then check to see if it's charging.

Yep, would have been right. I made the assumption it had to do with oil because it was low. Never thought about charging problems. BTW, it also blew my microwave during its last gasps. Coincidence? Maybe but it is a pretty big one. But between all the smoke alarms going off, the microwave, the sudden off/on of power, then the genset turning off on its own, I think it is all related.

 

[Zed254]

Search Ebay for "MILITARY MEP 802a 803a GENERATOR 24 VOLT 35A REPLACEMENT ALTERNATOR 8MR3005" . He's kind of proud of them, but they are available. A local alternator shop may be able to rebuild yours.

 

[Daybreak]

Howdy,
You might only need some parts too.

6115-01-368-2911 GENERATOR,DIRECT CURRENT 8MR3005C, MEP-802A, MEP-803A

Breakdown Parts List


​

View attachment SP1023_8MR_parts_list_web.pdf

 

[Gunny65]

Search Ebay for "MILITARY MEP 802a 803a GENERATOR 24 VOLT 35A REPLACEMENT ALTERNATOR 8MR3005" . He's kind of proud of them, but they are available. A local alternator shop may be able to rebuild yours.

Thanks. I live in a very rural area. No alternator shop is close unfortunately. Sometimes living rural, you gotta pay extra for what you want. I choose to live here anyway. LOL. Your help is appreciated.

 

[Guyfang]

You are assuming again. When you have power again, charge the battery's. The start the set. Measure what the alternator is putting out. If you have one or more bad battery's, they won't charge. You need to cover all the bases, before spending money.

Edit: If it is the alternator, and you do buy one, I still would get it fixed. Why? Well you have a spare. Or sell it, and maybe recoup some of your money.